定位系统及说明书约13世纪如今这项技术已广为人知，无需赘述。然而，对于一个拥有中世纪世界观的人来说，这大概堪称革命性的创举。
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.