The King Disappears

Mummers of concern rippled among the spectators that lined the River Thames in London, England.  One minute the boat was floating gracefully.  The next it started sinking, slowly disappearing from view until it could be seen no more.  Shouldn’t someone attempt a rescue?  After all, King James himself was on board the sunken vessel.

The crowd needn’t have worried.  The boat was no ordinary vessel.  It was the clever invention of Cornelis Drebbel, a Dutchman.  And its journey down the Thames in 1620 was no leisurely cruise.  It was a daring demonstration involving the King of England himself.

Drebbel had designed an unusual water craft.   Although it was made of wood like other boats of its time, Drebbel’s vessel was wrapped in greased leather, making it fully enclosed and airtight.  Oars extended through the sides, sealed with tight-fitting leather flaps to prevent water from leaking into the boat.  The boat was large enough to hold twelve oarsman and several passengers.

Drebbel’s boat was outfitted with two other unusual features.  One of these was a series of large leather bags that were strapped to the hull.  The other was a set of air hoses that extended above the boat.  These features permitted Drebbel’s vessel to do something no other boat could do...sink below the water, then bob back to the surface.

When the boat was afloat, the leather bags were flat and stoppered,  the air completely squeezed completely out of them.  At a moment’s notice, however,  Drebbel could open the bags, allowing water to gush inside, adding weight to the boat, and forcing it to sink beneath the surface.  Air hoses attached to floats rose to the surface, providing the men on board with oxygen.  By squeezing the water out of the bags, Drebbel could reverse the process, forcing water from the bags, making the boat lighter and causing it to rise again.

The daring demonstration worked wonderfully.  The boat sank four metres (12 feet), traveled for several kilometres underwater, then rose gracefully back to the surface.  The entire journey took three hours.  At the end, King James and the other passengers emerged safe and sound to declare that the world’s first submarine was a great success.

Extreme Facts

* Although the submarine was Drebbel’s most remarkable invention, he also designed and built microscopes, telescopes, thermostats, incubators, toys and clocks.  He discovered a way of making oxygen using chemicals and he may have used this process to replace the air hoses in other submarines he later constructed.

* Drebbel is so admired by scientists and inventors that a crater on the moon has been named after him.  The Drebbel Lunar Crater measures 30 kilometres (18 miles) in diameter.