定位系統與使用手冊約莫西元13世紀如今，這項技術早已廣為人知，無需贅述。然而，對懷抱中世紀世界觀的人來說，它或許是項革命性的發明。
英文原文
Locator System & Manual
c. 13th century
Today this technology is so well understood it needs no introduction. However, to someone with a medieval understanding of the world, it was probably revolutionary.