[Printed] Report of an Experiment tried in the Royal Laboratory at Woolwich. Result of Experiments tried on the Principle of Sir William Congreve's Patent for the Application of Chalk Lime-Stone and other Calcareous Substances in the Saving of Fuel. [Experiments, 1818 Dec 15-18 and 1819 Apr, attested to by Henry Dugleby, Chief Clerk, Royal Laboratory, and John Perks, Engineer to the City of London Gas Light Company, respectively]