Letter from John Dougan & Co from the Office of the Respirator, to Mountstuart Elphinstone, with enclosures regarding an account of the action and principle of the respirator invented by Mr Jefferys, testimonials, price, structure and so on
Letter from John Wedderburn at 53 Baker Street, to Mountstuart Elphinstone, enclosing Captain Poole's memorial to the Court of Directors, with certificates and testimonials