The engineer James Watt collaborated with the physician, Thomas Beddoes, in this project. This was Watt's only contribution to medicine. While much of Beddoes' work proved ineffective it did result in Humphrey Davy's discovery of the anesthetic effect of nitrous oxide. Digital facsimile from the Internet Archive at this link. In 1796 Watt published Supplement to the description of a pneumatic apparatus, for preparing factitious airs : containing a description of a simplified apparatus, and of a portable apparatus. Digital facsimile of the supplement from the Internet Archive at this link.