The Elements of Practical AstronomyMacmillan, 1899 - 264 pages |
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Common terms and phrases
adjustment American Ephemeris Ann Arbor apparent place apparent zenith distance ascension and declination azimuth chronograph chronometer correction circle readings clamp east clamp west coincidence collimation computed coördinates corresponding cosec determine Detroit Observatory difference direct double altitudes earth ecliptic Ephem Ephemeris equal equatorial Example eyepiece formulæ geocentric given graduated Greenwich mean horizon hour angle hour circle index correction instant latitude level constant Lick Observatory limb longitude lower culmination mean place measured meridian passage method micrometer readings micrometer wire middle wire moon moon's object glass observations observer's obtain parallax personal equation pivots polar position precession prime vertical proper motion reduced reflected image refraction right ascension rotation axis screw semidiameter sextant reading sidereal chronometer sidereal interval sin² solar star star's sun's tables telescope Therm tion transit instrument true zenith distance vernal equinox vernier vertical circle zero Δα Δθ
Popular passages
Page 10 - ... cos a = cos b cos c + sin b sin c cos A, sin a cos B = cos b sin c - sin b cos c cos A, sin a sin B = sin b sin A.
Page 18 - A solar day is the interval of time between two successive upper transits of the sun over the same meridian. The solar time at any instant is the hour angle of the sun at that instant.
Page 106 - SW 756), the court refused to disturb a conviction of murder on an objection based upon the fact that during the early stages of impaneling the jury two men were stationed on the afternoon of one day and the forenoon of the next day at...
Page 7 - The longitude of a place is the arc of the equator intercepted between the meridian of that place and some assumed meridian to which all others are referred.
Page 42 - His true position is in the diagonal of the parallelogram, whose sides are in the ratio of the velocity of light to the velocity of the earth in its orbit, which is as 190000 to 19.
Page 18 - A sidereal day is the interval of time between two successive upper transits of the vernal equinox over the same meridian.
Page 98 - Having made the adjustments of the index and horizon mirrors and of the telescope, as previously described, it is necessary to find that point of the arc at which the zero of the vernier falls when the two mirrors are parallel, for all angles measured by the sextant are reckoned from that point. If this point is to the left of the...
Page 124 - The straight line passing through the optical center of the object glass and the rotation axis and perpendicular to the latter is the collimation axis.
Page 222 - The magnifying power of a telescope is equal to the focal length of the objective divided by the focal length of the eyepiece.
Page 17 - A Solar Day is the interval of time between two successive transits of the sun over the same meridian; and the hour-angle of the sun is called Solar Time.