The Cartographer Who Ran Out of Comparisons

In 1856, British surveyor Andrew Waugh sat at his desk in Dehradun, India, staring at calculations that defied every mountain he had ever measured. Peak XV, hidden behind the closer ranges of Nepal, had been triangulated at 29,002 feet. Waugh had spent years cataloging the Himalayas, naming peaks by comparing them to one another — this one taller than that one, this ridge like a smaller version of that ridge.…