print, etching and aquatint printed in sepia, Mr Martyn's design for an aerostatic globe 1783, with descriptive key in English and French, published by Thomas Martyn, King Street Covent Garden London 2 October 1784. Scale 6ft : 1in. Image 33.5x27cm. Earliest English design for navigable balloon,using erroneous combination of sails oar and rudder