400 year old submarine mystery

Did a submarine stay submerged for three hours while journeying down the Thames in 1620?  Apparently, it did happen. Several commentators, particularly diarists, recorded the event, either as eye-witnesses or as anecdotes from reliable sources.

 The generally accepted story was that at some time before 1619 Cornelius Drebbel came to England from Europe and worked on several projects for the Royal Navy as well as carrying out independent scientific research. One of his innovations was a submersible propelled by oars. The submarine was successfully demonstrated in front of King James the First. Drebbel was inspired by observing the way fishing boxes drop below the surface and re-emerged as the rhythm of the oars on the boats towing them rise and fall. After a life time of invention and research Drebbel , it’s popularly believed, died in poverty in a London ‘ale house’ in 1633.

That’s the accepted story. However, the truth is a little more complicated and many people have doubted the claims made for Drebble’s submarine.  In fact, there were three, increasingly larger, versions of the original. The final model had six oars and could carry up to sixteen passengers. It was this version that was demonstrated in front of King James  and thousands of Londoners who lined the banks of the Thames, as it travelled, submerged at a depth of 15 feet for three hours, under the surface of the river from London to Greenwich.

Most of the doubts cast at the claims of the sub’s prowess – some ‘experts’ even suggesting the boat was never built – focus on the implausibility of the rowing Drebbelnauts being able to breathe in a confined space, under water, for up to three hours . However, one diarist records that Drebbel had invented a “cheymicall liquor,” which he kept in a class vessel aboard the sub. Drebbel, explained the writer, “would by unstopping [the] vessel speedily restore the troubled air.”  This is not as ludicrous as it sounds. The vessel could have contained ‘reactive potassium’, which is created by heating potassium nitrate. One of the properties of this “cheymicall liquor” is the ability to dissipate carbon dioxide. If Drebbel’s secret was potassium he probably had a second vessel onboard that contained oxygen, which is also produced when potassium nitrate is heated. Oxygen was not so named until 1775, before that it had been known as, “fire-air”, “vital air” and “elixir of life.”  The last of these terms was used Michel Sedziwoj who, in the late sixteenth century, was the first to describe oxygen’s  properties.  Dribbel referred to the gas  as the “quintessence of air.”

The sub’s method for diving and surfacing is not so contentious. Under their bench seats the Drebblenauts had large pig’s bladders. These were connected to the outside of the sub’s hull. To dive the bladders were untied and water was allowed to fill them. To surface the Drebbelnauts squeezed the water out and resealed the bladders.

If the idea of a submarine invented nearly four hundred years ago, and powered by pig’s bladders, oars and a mysterious “cheymicall” seem fanciful , bear in mind two things. First, Drebbel is credited with many other inventions, including the first two lens microscope, the first working thermometer, and a perpetual motion machine, which told the time, date, and season, and the intriguingly named “cooling machine.” Secondly, the BBC commissioned the building of a replica of Drebbel’s first four oar submersible. This was built, very successfully tested and is currently on display in Heron’s Square, Richmond upon Thames.