AstronomyDetermination of time, longitude, latitude, and azimuth . longations, orat upper and lower culminations, provided the sun be not too high; k Ursas Minoris, from itsgreater proximity to the pole and its smaller size, presents to the larger instruments a finer andsteadier object for bisection than Polaris; 51 Cephei is also advantageously used on account ofits small size. The star B. A. C. No. 4165, shown on the diagram, was proposed and used forazimuth work by Assistant G. Davidson. The apparent precessional motion of the pole in100 years is indicated by the direction and length of the
AstronomyDetermination of time, longitude, latitude, and azimuth . longations, orat upper and lower culminations, provided the sun be not too high; k Ursas Minoris, from itsgreater proximity to the pole and its smaller size, presents to the larger instruments a finer andsteadier object for bisection than Polaris; 51 Cephei is also advantageously used on account ofits small size. The star B. A. C. No. 4165, shown on the diagram, was proposed and used forazimuth work by Assistant G. Davidson. The apparent precessional motion of the pole in100 years is indicated by the direction and length of the arrow. The sun is employed only todetermine azimuths of inferior accuracy, generally in connection with the determination of themagnetic declination. 1 The statements made in a general and somewhat indefinite form in this paragraph may be stated in accurate mathematical form by derivingdA in terms of dt,d<p, dd, respectively, from the formula —sin t tan A = cos <p tan o—sin <p cos t (see p. 143), or from the formulas used in its derivation. No. EIGHTY-FOOT SIGNAL.
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Keywords: ., bookauthoruscoasta, bookcentury1900, bookdecade1910, bookyear1913
