Summary

Dava Sobel's "Longitude" tells the epic story of John Harrison, a self-taught clockmaker who solved the centuries-old problem of determining longitude at sea. For centuries, sailors could navigate by latitude, using the sun and stars, but accurately determining longitude remained elusive, leading to countless shipwrecks and lost lives. The inability to determine longitude not only threatened lives but also hampered trade and exploration. Nations offered immense rewards for a solution. Sobel masterfully interweaves Harrison's tale with the broader history of longitude, exploring various proposed solutions, from astronomical methods to outlandish schemes involving wounded dogs and strategically placed cannons. The book introduces us to a cast of characters, from astronomers like Edmond Halley and Nevil Maskelyne to royalty like King George III. While astronomers favored celestial solutions like the lunar distance method, Harrison pursued a more grounded path: the creation of a clock that could keep precise time at sea, unaffected by temperature changes, ship motion, or variations in gravity. Harrison's journey spans decades and involves the creation of four groundbreaking timekeepers, known as H-1 through H-4. Each clock represented a leap forward in precision timekeeping, incorporating innovations like the gridiron pendulum and grasshopper escapement, bimetallic strips, and diamond pallets. Harrison faced constant skepticism and resistance from the scientific establishment, particularly from Maskelyne, the Astronomer Royal. They favored astronomical methods and viewed Harrison, a mere "mechanic," with suspicion. The book details the rigorous trials Harrison's clocks underwent, including voyages across the Atlantic. These trials not only tested the clocks but also Harrison's patience and resolve. Sobel vividly describes the political intrigue, scientific rivalries, and sheer human drama that surrounded the quest for longitude. She highlights the contrast between Harrison's practical, hands-on approach and the more theoretical methods favored by the astronomers. The book culminates with Harrison's eventual triumph. With the support of King George III, he finally received recognition and the prize money he deserved. "Longitude" is not just a story about a scientific breakthrough; it's a compelling narrative about perseverance, ingenuity, and the clash between tradition and innovation.