Not online, unfortunately

Hydrogen production for ballooning during the French Revolution: An early example of chemical process development
Janis Langinsa
Annals of Science, Volume 40, Issue 6, 1983, pages 531-558

When hydrogen-filled balloons were used for military purposes during the French Revolution, the method used to produce the hydrogen lifting gas was the passing of steam over incandescent iron. This paper describes the way this method was developed from the laboratory-scale experiments first performed by Lavoisier to regular field operation where balloons with a volume of 12,500 cubic feet were filled from specially designed reactors. The method was ultimately abandoned, but its development and demise provide a valuable case study of early science-based technology.

http://www.tandfonline.com/doi/abs/10.1080/00033798300200381