1Marcus Dyson to Thomas Jefferson, 6 May 1816 (Jefferson Papers)
I hope you will pardon the liberty I have taken in addressing you, I have no other apology to offer except total unacquaintance with any person who could give me the information I desire, the eminent rank you hold in this Country, your acquaintance in Europe , & great reading, led me to hope you could, my enquiry is this, whether oxygen gas can be pressed with same facility as atmospheric air,...
2Enclosure: Marcus Dyson’s Drawing and Description of a Device for Breathing Underwater, [ca. 6 May 1816] (Jefferson Papers)
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 quanty 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...