Imagine sailing out to the open waters of the sea, far from visible land, and trying to navigate to your destination. Prior to the mid-18th century, that’s what most sailors had to deal with because, though they could read star charts, they didn’t know how to accurately measure longitude. And without that information, many ships sailed wildly off course, often to their rocky demise.
Measuring and identifying latitude has been an easy exercise for experienced sailors for millennia, and even Christopher Columbus made it to the Americas following a single latitude. Longitude is a different matter, because it depends on time–the time difference between the ship and its point of origin. The problem was that there were no clocks that stayed accurate enough on a ship because the rolling action and the change in climate experienced on a long sea voyage, both of which affected the timing mechanism.
In 1714, The British Parliament issued the Longitude Act which established a prize, worth several million dollars in today’s money, for anyone who could build a clock that allow a “practicable and Useful means of determining longitude.”
This is the story of English Clockmaker John Harrison, who with no formal education or training in watchmaking, was able to outwit the scientific elite of his time. It took forty years and several iterations of his clocks, known as H-1 through H-5, as well as fighting against sabotage and jealousy from rivals to finally achieve one of the most important scientific breakthroughs in history.
“Longitude” is a wonderful historical book filled with wonder, intrigue, failure and ultimate success.
Review written by: Larry Pollack
Pair It With:
Boddington’s Pub Ale: An English pale ale that is smooth, creamy and a little malty. This has a floral nose and slight bitterness that is perfect for sipping.