Surveying navigation and astronomy instrument

摘要

An instrument in the form of a cross with an attached scale C of degrees and centrally fixed, weighted plumb line or bar F that acts as an indicator.The cross piece B acts as a sight and the lower part of the perpendicular upright A acts as a fulcrum.Where the upper part of the perpendicular upright acts as a further sight line for observing angles horizontally. Used for construction projects,navigation,astronomy and art.