Chronometry is the science of measuring time with precision. It involves the development and use of various timekeeping devices, such as clocks and watches. The goal of chronometry is to achieve accurate time measurement, which is essential for navigation, scientific research, and daily life. One of the most significant advancements in chronometry was the invention of the marine chronometer by John Harrison in the 18th century. This device allowed sailors to determine their longitude at sea, revolutionizing maritime navigation. Today, atomic clocks represent the pinnacle of chronometric technology, providing the most accurate timekeeping available.