A Philosophical Dissertation on the diving vessel projected by Mr Day, and sunk in Plymouth Sound

Coronavirus reopening

Visitor notice: Royal Museums Greenwich will be closed from Thursday 5 November until Wednesday 2 December in line with government guidelines. If you have booked a ticket for this period please contact bookings@rmg.co.ukFind out more

The first recorded death of a submariner, an incident which took place in June 1774.

Our first item of the month for 2014 looks at another, albeit more grizzly, first: the first recorded death of a submariner, an incident that took place 240 years ago this year, in June 1774.

Title page of N.D. Falck's Philosophic DissertationRelatively little is known about the life of John Day, a millwright from East Anglia, but the account of his unfortunate demise and the subsequent analysis of his failed experiment, is the subject of Nikolai Detlef Falck’s 1775 publication A philosophical dissertation on the diving vessel projected by Mr Day, and sunk in Plymouth Sound (RMG ref: PBB8244).

Falck (1736–83) wrote a number of works on medicine, science and technology, including The Seaman’s Medical Instructor (1774) and An Account and Description of an Improved Steam-engine (1776).  His 1775 work provides an account of John Day’s ambitious attempt to construct a diving vessel and descend into the waters of Plymouth Sound. Day had confidence in his scheme, following an apparent previous success, where he had allowed the tide to flow over and cover a chamber within a boat where he was able to stay for over six hours.  Falck does not know where this prior enterprise took place, however the Annual Register for the year 1774 suggests this was in the Broads near Yarmouth and that Day descended 30 feet.

Falck paints a relatively unflattering picture of John Day, based on reports he gathered in Plymouth:

His temper was gloomy, reserved and peevish; his disposition penurious; his views pecuniary; and he was remarkably obstinate in his opinion and jealous of his fame.  But withal, he was allowed to be penetrating in his observations; acute in his remarks; faithful to his patron; and unshaken in his resolutions. [p.2]

Perhaps encouraged by his earlier success, Day enlisted the financial support of Charles Blake to fund a demonstration on a larger scale. A 50-ton sloop called The Maria, described as 'old but yet in a very good condition', was purchased and fitted out to include an 'air chamber' of 12 feet by 9 feet by 8 feet for its passenger. The air chamber was re-enforced against the pressure of the water with 'stout stanchions' on all sides. External ballast, consisting of 'twenty rough stones, each of a ton weight', was attached to the underside of the vessel by rope. Sluices in the forepart of the vessel allowed water to enter.

The Maria carried a rudimentary system of signals to allow her passenger to communicate with the outside world, to advise about the state of his health during his stay underwater:

On the deck of the chamber were fixed three buoys of different colours … the white was to denote his being very well; the red, indifferent; and the black his being very ill. [p.6]

Unfortunately, Day would never use the signals. The difference between his prior submersion of 30 feet and the approximate 20 fathoms (120 feet) at Plymouth was, seemingly, too much for The Maria. Falck describes the scene shortly after Day began his descent at 2pm on 20 June:

In a few minutes after his departure the water on the spot became greatly agitated; but various are the accounts of this; some of the men told me it was like a kind of eddy that always ensues on the sinking of anything; but Mr Black thinks it was attended with a violent ebullition of air. [p.9]

Whilst the sinking was undertaken in secret, word of the experiment spread and crowds gathered ready for Day’s scheduled return to the surface at 2pm on 21 June, 24 hours after his descent. The Maria did not appear. With the night of 21 June passing and still no sign of The Maria, Day or his status buoys, expectation turned to disappointment and concern. A considerable rescue effort was undertaken by the Plymouth authorities:

Lord Sandwich … ordered up all the aid which the dock-yard could afford, for weighing her up; three days passed under the continual endeavours of two hundred men, lighters, cables, and other requisite materials; but in vain; he was left to be numbered amongst the dead. [p.9]

Plate showing a cross section of The Maria
Plate showing a cross section of The Maria
Falck expends considerable analysis on why the descent of The Maria was unsuccessful. Whilst pressure would appear to be the obvious culprit, Falck suggests that the chilling of the air inside the air chamber to create a near vacuum combined with the insufficient volume of air to sustain life for the anticipated 24 hour descent were the causes of the failure.

In July of 1774, Falck himself attempts to mount a recovery of The Maria. The first reason he gives for this is both ambitious and hugely optimistic: he hopes to be able to find and resuscitate John Day:

… having been fortunate enough to restore to life persons that have been drowned, (the method of which I have fully stated in my Seaman’s Medical Instructor) I own that my sanguine expectations were flattered, notwithstanding the length of time he had remained in this suspense, since we have had instances of some extraordinary recoveries, with circumstances less favourable than here. [p. 22]

His second reason for the recovery, to identify the cause of the experiment’s failure, appears a slightly more achievable objective. He approached Day’s financial backer Charles Blake, who offered the vessel as salvage if recovered. Approaches to Lord Sandwich to offer assistance were politely declined by his lordship. 

On 30 July 1774, Falck believes he has located the vessel 'a marine searcher (of my own contrivance)' which resembled a spiked sounding lead made of iron with which he could distinguish wood from stones beneath the water. With bad weather and technical difficulties taking their toll on his assembled team, Falck continued recovery efforts in Plymouth until 21 October 1774 but he ultimately failed in his effort to raise The Maria or rescue Day.

Plate showing recovery equipment, recovery plan and Plymouth Sound
Plate showing recovery equipment, recovery plan and Plymouth Sound
The wreck of The Maria and the remains of John Day were never recovered. Falck’s epitaph to The Maria and John Day remains: 'she was sunk at two o’clock… and Mr Day descended with her into perpetual night!'

The Caird Library has a range of material relating to submersibles and submarines. To search our collections, please visit our online Library catalogue at: www.rmg.co.uk/librarycatalogue.

Gareth, Library Manager

Search the Archive catalogue

Search the Library catalogue