[Printed report] 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. 1819 May 3. [3p. on 1 leaf. Experiments, 1818 Dec 15-18 and 1819 Apr 29, attested to by Henry Dugleby, chief clerk of the Royal Laboratory, Woolwich, and John Perks, engineer to the City of London Gas Light Company. Part A 837/4 of the Goodrich archive]