Enclosure: Marcus Dyson’s Drawing and Description of a Device for Breathing Underwater, [ca. 6 May 1816]
Enclosure
Marcus Dyson’s Drawing and Description of a Device for Breathing Underwater
[ca. 6 May 1816]
EXPLANATION
A. The reservoir made of copper in form of an half oval (flat Side next the body) capacity 4 Quarts, with an half inch opening
B The stop cock, inserted in the reservoir, which by turning the handle will emit air in any quantity wanted,
C A tube half inch diameter leading from the Stop cock into the half Globe D
D In form of a half Globe capacity 1 pint which closely covers nose & mouth
E a tube 1 inch diameter nearly circular one end commencing at D. with a Valve opening downward & the other end also joining D with Valve opening upwards having numerous Small holes
F in form of a pair of bellows, joining E with 2 Valves opening downwards
Experiment
having provided yourself with a water proof1 covering, fix the Reservoir upon your breast (being filled with air) & the half Globe closely upon your face, turn the cock B. air will rush through the tube C. into Globe D. which you will inspire & again respire, which air having no other escape will be forced into the tube E. where the water coming through the small holes will absorb the carbon, & carry it off through the bellows F. by being opened & shut by the hand. the Valves preventing it returning, the air will pass on & be still further robbed of its carbon by the water trickling2 down & pass through the Valve into the Globe D & be again inspired, the quantity of Oxygen therefore wanted will be but 1⁄10 from the reservoir of the bulb of each inspiration
MS (DLC: TJ Papers, 207:36847); written entirely in Dyson’s hand on both sides of address cover of covering letter; undated.
1. Manuscript: “proff.”
2. Manuscript: “tricling.”