Crichton Miller, an amateur historian and researcher has declared that the unidentified artifacts found after being hidden for millenna in the Queens Chamber of the Pyramid of Khufu in 1872. He hypothesises that the Cross is the missing instrument of Thoth and it's associated mathematics including Pi. Read about here; www.farshore.force9.co.uk/am celt.htm HA HA SHE CRIED, SHOOK HER WOODEN LEG AND DIED
Looks like Miller is patenting a primitive sextant. I see no reason why ancient man, with a knowledge of some form of mathematics, couldn't use such a device to navigate. The Chief Navigator aboard the USS Jerimiah O'Brien, a Liberty Ship docked in San Francisco, taught me how to use a sextant, and they're deceptively simple. I don't see why ancient navigators and surveyors couldn't tie two sticks together at right angles and use it for something similar.