Richard Lange was Ferdinand Adolph's eldest son, and he was obsessed with precision. He was the one who spent years working on balance spring alloys and left behind a patent that watchmaking still uses today. The collection bearing his name follows suit, borrowing the regulator dials of scientific observation watches, where legibility takes precedence over everything else. This all makes the Terraluna the most surprising thing in that lineup, because the most instrument-minded line that A. Lange & Söhne builds ended up producing what is quite possibly its most romantic watch.