A treatise on surveying and navigation

apparent altitude barometer called chains circle circumferentor compass compute correction cosine course and distance decimal definite degree difl'erence direction divide draw earth east equal equation error example feet field fig figure find the area finding first give given point Greenwich Hence horizontal parallax hypotenuse inches instrument latitude and departure logarithm longitude measure meridian altitude meridian distance meridian line miles moon moon’s Multiply Nautical Almanac needle noon number corresponding object observer parallel perpendicular plane plane sailing plumb line polar distance polygon problem radius reflected represent right angled right ascension screw semi-diameter setting and drift sextant ship sail side sine spherical trigonometry square star station subtract sun’s survey surveyor Tang tangent trapezoid traverse table triangle trigonometry true altitude true distance vernier scale Whence