Roman Mars

If you pulled into harbor with the greatest level of accuracy, just 30 nautical miles or half a degree of longitude, you'd get the highest prize.

With the modern equivalent of around 3 million bucks on the line, all sorts of people came out of the woodwork with wacky solutions involving, among other things, cannons, dogs, and magic powder.

In the world of navigation, astronomy reigned supreme.

Astronomers were men of science, and over the many, many years, they had been inching closer to a solution.

But for all their high towers and stargazing, no one had managed to bring the issue of longitude within reach.

Historical records of his early life are scarce, but we know that he was born in 1693 and generally described as a sort of single-minded, eccentric guy who was a genius when it came to clocks.

Harrison's timekeepers were some of the best, most accurate clocks in the world, which made him particularly well-suited to finally solving the longitude problem.

The whole scientific community had known for a long time that it was hypothetically possible to calculate longitude using time differences.

You just needed to know your own local time and the time back at your home port.

And you can get even more precise than that.

One hour equals 15 degrees of longitude.

This might sound like a pretty simple solution to the problem of longitude at sea.

Just set a clock before leaving and take it on board your ship.

During this era, all clocks were kind of crappy.

But bring one of those crappy clocks on board a ship and it was useless.

These were mostly pendulum clocks.

And you can imagine how well a pendulum clock would work on a rocking ship.

But where others saw problems, John Harrison saw an opportunity.

He thought he could solve longitude not by looking at the stars, but by building a better clock.

He also solved the problem of temperature by combining complementary metals, steel and brass, that expand at different rates and at different temperatures, which stopped the metal components from changing shape.