To measure the difference in elevation between poles, surveyors used an optical level—a telescope on a level base—placed halfway between the poles.

为了测量两极之间的高程差，测量员在两极中间的一个水平基座上使用了光学水准望远镜。

youdao

The top of the clock tower is leaning one-and-a-half feet off a level position, according to surveyors, and getting worse each year.

据测量人员检测，钟楼顶部已水平偏移1.5英尺(约0.46米)，而且情况逐年严重。

youdao