This led to all-too-frequent catastrophic wrecks.
The earth’s rotation makes the heavens generally useless, and with no landmarks out at sea, one was essentially sailing blind. However, orienting oneself along longitude, the east/west axis, is much more difficult. One can easily enough navigate from north to south, or along latitude, with astronomical knowledge and a sextant. The Zenith Defy Lab with its ☐.3 seconds per day accuracy would’ve been burned at the stake as a witch had it shown up in 1714 as a solution to everyone’s problems.Īs Sobel details, navigation at sea before the invention of marine chronometers was thwarted by the “longitude problem”. I wonder what her thoughts are now, some quarter century since then, as mechanical wristwatches catch up to and even surpass the accuracy of Harrison’s exquisite machines. If this was present in Sobel’s mind when she wrote Longitude, she makes little reference to it. I imagine the ’90s might’ve been the perfect moment to reflect back on a time when extreme accuracy in measuring time was a pipe dream ranked among human flight and space exploration. US Naval Observatory Alternate Master Clock, accurate to three nanoseconds (0.000000003 seconds) No better time to look back However, many governing bodies and organizations still require standalone chronometers (now often quartz) and someone trained to use one. In the ’90s, most seafaring vessels switched over to satellite-based computerized navigation systems. By 1995, Sobel had witnessed the proliferation of relatively highly accurate quartz time-telling and was beginning to see the spread and use of personal devices with signal-controlled time. As the book pertains to characters and events long since dead and passed, a publication date of more than 20 years ago has little bearing on the book’s readability and engagement. Without Harrison and his chronometers, Great Britain would not have had the success it did in establishing and maintaining its empire, making one British astronomer’s personal vendetta against Harrison and his chronometers all the more damning.ĭava Sobel’s Longitude was originally published in 1995. John Harrison is the father of marine chronometers, the precise timing instruments that allowed ships from the 1700s into the 1900s to navigate by longitude. It’s a book about ingenuity, dedication, betrayal, eventual triumph, and a great deal of hard-earned money. Recommended by my father, Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time by Dava Sobel ended up being exactly the watch-adjacent content I was looking for. Learn more about Instacart pricing here.One can only look at watches for so long before the obsession requires other inputs. Pick up orders have no service fees, regardless of non-Instacart+ or Instacart+ membership. Instacart+ membership waives this like it would a delivery fee.
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