234 Life of Count Rumford. 



meetings, and which, being frequented by people from 

 all parts of Great Britain, he hoped would be another 

 advertisement of his improvement. He did the same 

 for the chimneys of Devonshire House, and for the 

 dwellings of Sir Joseph Banks, the Earl of Besborough, 

 the Countess-Dowager Spencer, Melbourne House, 

 Lady Templeton's, Mrs. Montague's, Lord Sudley's, 

 the Marquis of Salisbury's, and a hundred and fifty 

 others in London. He instructed a firm of bricklayers 

 in his method so as to give them constant employment. 

 He found that the saving of fuel which he effected, 

 while gaining increased warmth, amounted to from one 

 half to two thirds. He made use of his own room in 

 the Royal Hotel, Pall Mall, for trying experiments in 

 the construction of fireplaces and chimney-flues; and he 

 enlisted the co-operation of Mrs. Hempel, the owner 

 of a large pottery in Chelsea, for manufacturing the 

 parts of new materials in her line, and of Mr. Hopkins, 

 the King's ironmonger, for materials in his line, to aid 

 in carrying out his own designs. Giving very simple 

 and intelligible information about the philosophical 

 principles of combustion, ventilation, and draughts, he 

 prepared careful diagrams to show the proper measure- 

 ments, disposal, and arrangements of all the parts of a 

 fireplace and a flue, at the same time announcing that 

 he had no purpose to take out a patent for any of his 

 inventions or improvements, but left them wholly free 

 to the public. The cure of smoking chimneys and the 

 economy of heat were found to depend upon much the 

 same improvements applied to the construction of fire- 

 places. He noticed that, in most of those which he 

 examined, the heat which was radiated so as to warm an 

 apartment was scarcely a fifth part of what was gen- 



