## The Elements of Practical Astronomy (Google eBook) |

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### Common terms and phrases

adjustment American Ephemeris Ann Arbor apparent place apparent zenith distance ascension and declination astronomical azimuth chronograph chronometer correction circle readings clamp east clamp west coincidence collimation computed corresponding cosec determine Detroit Observatory difference diurnal motion double altitudes earth ecliptic elongation Ephemeris equal equatorial Example eyepiece flexure formulae 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 circle method micrometer readings micrometer wire microscope middle wire moon moon's Nebula object glass observations observer's obtain parallax personal equation pivots plane position precession probable error proper motion quantities reduced refraction reversing right ascension rotation axis screw semidiameter sextant sextant reading solar standard stars star's sun's tables Therm tion transit instrument true zenith distance vernal equinox vernier vertical circle zenith telescope zero

### Popular passages

Page 8 - ... 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 16 - 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 104 - 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 5 - 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 40 - 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 16 - A sidereal day is the interval of time between two successive upper transits of the vernal equinox over the same meridian.

Page 96 - 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 122 - 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 220 - The magnifying power of a telescope is equal to the focal length of the objective divided by the focal length of the eyepiece.

Page 15 - 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.