An Introduction to the Elements of Practical AstronomyLongman, Brown, Green, and Longmans, 1853 - 118 pages |
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Page 5
... light received from the sun , becomes darkened , and therefore invisible when that light is intercepted from it by ... ray of sun - light could reach us , until , by the combined effect of the motion of the satellite and of the rotation ...
... light received from the sun , becomes darkened , and therefore invisible when that light is intercepted from it by ... ray of sun - light could reach us , until , by the combined effect of the motion of the satellite and of the rotation ...
Page 7
... light to the point where its effect is observed , but only a transmission of this oscillatory motion , which is ... ray of light " must be understood to have the same meaning as regards light , that the term wave has with reference to ...
... light to the point where its effect is observed , but only a transmission of this oscillatory motion , which is ... ray of light " must be understood to have the same meaning as regards light , that the term wave has with reference to ...
Page 8
James R. Christie. REFLEXION AND REFRACTION OF LIGHT . 12. Thus if AB were the course , in air , of a ray of light , which impinged at B upon the plane surface EF of a material body ; then if BD be perpendicular to EF , and we make the ...
James R. Christie. REFLEXION AND REFRACTION OF LIGHT . 12. Thus if AB were the course , in air , of a ray of light , which impinged at B upon the plane surface EF of a material body ; then if BD be perpendicular to EF , and we make the ...
Page 13
... ray of light emanating from that star and impinging upon the point of observation , makes a greater angle with the plane which is tangential to the surface of the earth at the point whereon we stand , than the ray of light emanating ...
... ray of light emanating from that star and impinging upon the point of observation , makes a greater angle with the plane which is tangential to the surface of the earth at the point whereon we stand , than the ray of light emanating ...
Page 14
... ray of light from the star ; the plane ZOAS will be perpendicular to NAH ; and N being the point of the horizon mentioned above , NOA , its equal NZA , or the arc NA , will be the azimuth of star . The point Z in which the radius CO ...
... ray of light from the star ; the plane ZOAS will be perpendicular to NAH ; and N being the point of the horizon mentioned above , NOA , its equal NZA , or the arc NA , will be the azimuth of star . The point Z in which the radius CO ...
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Common terms and phrases
Aldebaran Almanac altitude and azimuth amount apparent noon Aquarii Arietis azimuth instrument called celestial body celestial equator celestial sphere course declination determination deviation difference direction diurnal motion Eclipse Reapp elapsed equal equator equator art find the latitude find the longitude fixed stars formula Greenwich mean heavens horizon horizontal parallax instant Jupiter Leonis line of collimation local mean longitude lunar distance mean noon mean solar interval measured middle wire minutes and seconds moon moon's bright limb moon's centre November obtain orbit parallel pass the meridian perpendicular Piscium place of observation point of Aries polar distance pole position prime vertical radius ray of light refraction Regulus right angles Right Ascension rotation satellite semidiameter sidereal day sidereal interval solstice subtracted sun's centre surface Table Tauri telescope terrestrial tion transit true distance values vernal equinox vernier vertical circle vertical plane z.sin zenith distance
Popular passages
Page 8 - When a ray of light passes from one medium to another, it is refracted so that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the velocities in the two media.
Page 33 - Find the latitude of the place and the declination of the star. What instrument would you use, in making these determinations and why ? 3. Find the declination of a star whose meridian zenith distance in a place whose latitude is 50° 22' i« 70° 10
Page 34 - The names of the signs of the zodiac are: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, and Pisces.
Page 57 - PM was 70° 58', the height of the eye being 21 feet above the surface of the sea. Required the true latitude of the ship ? Answer, 39° 28' N. 2. Being at sea in latitude 50° 40
Page 32 - ... the altitude of the pole is equal to the latitude of the place (art.
Page 102 - December 37 for the sake of convenience. This inclination is ever varying, as well from the effect of its mean diminution, as of the nutation of the earth's axis: it is an important element in deducing...
Page 39 - Both days are divided into 24 hours ; each hour into 60 minutes ; and each minute into 60 seconds ; the seconds are sub-divided decimally.
Page 102 - The longitude of any place is the arc of the equator, intercepted between the meridian of that place and the first meridian; the longitude, therefore, is the measure of the angle between the two meridians.
Page 3 - Since an oblate spheroid is generated by the revolution of an ellipse about its minor axis, the equator and all the sections of the spheroid parallel to the equator are circles, and all sections made by planes passing through the axis of revolution are equal ellipses. Let a and b represent the lengths of the semi-major and semi-minor axes of this meridian ellipse, which...
Page 67 - The disciples of Plato contributed not a little to the advancement of optics, by the important discovery they made, that light emits itself in straight lines, and that the angle of incidence is always equal to the angle of reflection. Plato terms colours " the effect of light transmitted from bodies, the small particles of which were adapted to the organ of sight.