Theodolite

By Deane Barker

This is the common land surveyors tool, where someone looks through an eyepiece at specific points to measure angles and determine land boundaries.

Why I Looked It Up

In How Infrastructure Works:

British surveyors lugged half-ton theodolites from the southernmost tip of India…all the way up the spine of the subcontinent to the Himalayas and Mount Everest…