A Philosophical Dissertation on the Diving Vessel Projected by Mr. Day, and Sunk in Plymouth Sound;

FALCK (Nikolai Detlef).

Data di pubblicazione: 1775

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2 folding engraved plates, 4to., lacks half title and errata slip, quarter calf over marbled boards, red morocco label to spine titled "Miscellanies" with number 49 in the panel below, paper to boards scuffed and peeling in two small areas, otherwise very good. Bound between two unrelated contemporary works: LANGHORNE. The Country Justice. A Poem . Part the First - Third. London, T. Becket, 1774-7. & BLAYNEY (Benjamin). A Dissertation by way of Inquiry .&c. Oxford, At the Clarendon Press, 1775. [iii]-vi, 58, [4]pp. London, Printed by the Author, and sold by B. Law, . E. and C. Dilly, . and J. Walter, The sorry tale of a Yarmouth labourer John Day, who though "illiterate and indigent in his circumstances" had a bold and unshakable confidence in his ability as a submariner. His efforts did find him the fame that he was "jealous of" - but alas - his notch on the belt of history was the unconverted title of first recorded submarine shipwreck fatality.    Day's initial experiments involved using the tide to submerge him in a diving-bell style vessel, which perhaps contributed to his crucial misunderstandings of the pressure implications of vertical submersion. After a modest but much exaggerated success, he took his expanded proposition to professional gambler Christopher Blake Esq. as "an affair by which money might be won". Blake took the bait - he advanced Day £350 to construct the vessel and offered 10% of all winnings from wagers. With this, Day purchased a 50 ton sloop, the Maria, and employed a Plymouth shipwright Mr. Hunn to modify and refit her to his specifications.   These modifications entailed the creation of a sealed internal chamber of 12ft by 9 by 8, with a volume of "75 hogshead" of air - "the whole frame of the chamber was seared, bolted, and secured with knees on all sides within." Alongside this, an internal ballast of 10 tons of limestone was added, plus an additional mechanism by which "twenty rough stones, each of a ton weight" were suspended beneath the sloop with a means to detach from them rigged to the internal chamber, ostensibly with a thought to allow Mr. Day to loose them and rise at the end of his submersion. There were three coloured bouys also rigged to controls in the chamber which could be released to indicate the aquanaut's state of health: white for very well, red for indifferent, and black for very ill.    At 2pm on the afternoon of 20th June 1772, the Maria was towed into out into Plymouth Sound, and was sunk. At this point, as Falck concisely puts it, "Mr. Day descended with her into perpetual night". The locals gathered on the cliffs to await his triumphant emersion, but no boat nor bouy was seen. Much was made of the possible effect of the dramatic drop in temperature at the depth Mr. Day submerged to, but the essential miscalculation was in reality a simple one of pressure. As Edwn Gray puts it in his book Disasters of the Deep: A Comprehensive Survey of Submarine Accidents & Disasters: "Water pressure increases by 15 pounds per square inch for every 30 feet of depth. At 130 feet Day's boat would have been subject to pressure of more than 60 pounds per square inch and it is highly probable that Maria broke up long before she ever reached the bottom of the sea."   Thereafter is an extensive account by the author, naval doctor Nikolai Falck, of his attempts to raise the wreck. His hope was that in examining the cause of failure, it might be possible to "do justice to the memory of this unfortunate man". He also suggested, in a projection every bit as fantastical as Day's own, that there might still be a chance of reviving the long drowned man "whose death I presumed not to be real, but a mere cessation of the animal functions, and whose congealed mass of blood would remain a considerable time, in so cold a region, before a chance of putrefaction could take place". Falck's efforts are unsuccessful on every count, but he does record many interesting observations on the problems and conditions.

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• Titolo: A Philosophical Dissertation on the Diving Vessel Projected by Mr. Day, and Sunk in Plymouth Sound
• Data di pubblicazione: 1775
• Rilegatura: Rilegato