202.

Colonel X was a Welsh surveyor, geographer and Surveyor-General of India from 1830 to 1843. X was largely responsible for completing the section of the Great Trigonometric Survey of India along the meridian arc from the south of India extending north to Nepal, a distance of approximately 2,400 kilometres (1,491 mi). The survey was started by William Lambton in 1806 and lasted several decades. In 1865, Y was named in his honour despite his objections. It was surveyed by his successor, Andrew Waugh.