A Treatise on Practical Astronomy: As Applied to Geodesy and Navigation

accuracy adjustment altitude angle apparent applied approximation assumed axis azimuth becomes centre chronometer circle clamp clock coefficients collimation computation considered constant convenient correction corresponding culmination declination derived determined difference differential direction earth east effect employed ephemeris equal equations error example expressed follows formulę given gives horizon instrument interval known latitude limb longitude manner mark mean measured meridian method middle moon moon's motion necessary observed obtained parallax passing plane position practically quantities reading reduced referred refraction respectively result right ascension shown sidereal star Substituting Suppose taken telescope thread tion transit true unknown quantities values vertical Washington weight write zenith distance