1 ene 400 año aC - Cross Staff

Descripción:

A stick or pole with length markings; most staffs are much more complicated than that, and usually contain a number of measurement and stabilization features. It's used In astronomy and navigation for a simple device to measure angles, later replaced by the more precise sextants and in surveying (and scientific fields that use surveying techniques, such as geology and ecology) for a vertical rod that penetrates or sits on the ground and supports a compass or other instrument.