Chronometer

Original content by: Dayne Rugh

zoomable artifact image here

About This Artifact

Throughout the history of navigation, dozens of different nautical instruments aided sailors and navigators in finding their way across the Earth's oceans.  However, the chronometer is one of those nautical instruments that truly revolutionized the world of natvigation.  The chronometer was the second piece of the puzzle for determining one's coordinates out at sea, a feat that was virtually unachievable for centuries.  The world is a vast place, and every location on Earth has a particular coordinate that is identified in degrees of latitude and longitude.  Seafarers since ancient times have been measuring latitude, and by the Age of Exploration and European colonization, mariners had sophisticated instruments to measure degrees of latitude, the most famous being the sextant.

However, while sailors could measure latitude using a well-established system of readings by celestial objects in the sky, such as the sun and the North Star, determining longitude was a far more difficult task, as determining longitude depended upon knowing a sequence of times.  More specifically, you had to know two different times:  the time on your ship, and the time at a Prime Meridian.  In order to tell what time it was on your ship, you actually didn't need a clock, because as soon as the sun reached the highest point in the sky, you knew it was 12:00 noon.  By taking an accurate sighting of the sun at noon, you would have your first time!  Knowing what time it was at a Prime Meridian required a clock, and thus, a problem arose.  Before the 1700s, no clock that existed could keep an accurate enough time to use for these measurements.  With this in mind, John Harrison set out to create what became known as the modern chronometer, changing the world of navigation forever.

Born in 1693, Harrison was the son of a carpenter.  At a very early age, he developed a knack for tinkering, making him a perfect candidate to develop an accurate timepiece.  In 1714, the English Parliament passed the Longitude Actm which offered a reward of 20,000 British pounds (millions of dollars in today's money) to whoever could develop a clock that could keep accurate time.  By 1735, Harrison developed his first timepiece and was awarded a sum of 500 pounds.  Harrison labored for decades, improving his invention, but was met with a large amount of pushback from those who discredited his work.  Although he patented the device that met the Longitude Act's standards, it took four more improved timpieces and a series of payments until Harrison was finally paid fully for his reward in 1773 — almost 40 years later!  Harrison's contributions to the nautical world remain legendary, and a testament that hard work and extreme patience can lead to tremendous success.

Questions for Further Thought

  1. John Harrison labored for close to 40 years to create the perfect chronometer timepiece, and just as long for him to receive full recognition from Britain. Does it seem fair that it took so long to be fully recognized? Why do you think he didn't give up?
  2. What advantages do you see for the British government offering a reward for the creation of a particular invention? Why do you think they decided to offer a prize in the first place?
  3. Did you ever have an idea for an invention that you thought could change the world? Or that people would take interest in? What about any improvements to inventions that already exist?