40 Biographical Memoir of Count Rumford. 



In one of his eslabllshments at Munich, three women were suffi- 

 cient to prepare a dinner for a thousand persons, and they burnt only 

 ninepence worth of fuel. The kitchen which he constructed in the 

 Hopital de la Pieta at Verona, it still more perfect, there being burnt 

 in it only the eight part of the wood which was formerly consumed. 



But it was in the employment of steam for heating, that Count 

 Rumford, so to speak, surpassed himself. It is known that water 

 kept in a vessel which it is unable to burst acquires an enormous 

 heat. Its vapor, at the moment when it is let loose, carries this heat 

 wherever it is directed. Baths and apartments are thus heated with 

 wonderful quickness. Applied to soapworks, and especially to dis- 

 tilleries, this method has already enriched several manufacturers of our 

 southern departments ; and in the countries where new discoveries 

 are more slowly adopted, it has offered immense advantages. The 

 brew-houses and distilleries of England are heated in this way. In 

 them a single small copper caldron boils ten large wooden vats. 



Count Rumford went so far in his improvements as even to econ- 

 omise all the heat of the smoke, which he only allowed to issue 

 from his apparatus after it had become almost perfectly cold. A 

 person justly celebrated for the elegance of his mind, said to him that 

 he would soon cook his dinner with his neighbor's smoke. But it 

 was not for himself that he sought economy. His varied and often 

 repeated experiments, on the contrary, cost him much, and it was 

 only by dint of lavishing his money, that he taught others to save 

 theirs. 



He made nearly as many researches on light as on heat, and among 

 his results, the following observations are principally worthy of notice ; 

 that flame is always perfectly transparent and permeable to the light 

 of any another flame ; that the quantity of light is not in proportion 

 to that of the heat, and that ii does not depend, like the latter, upon 

 the quantity of matter burnt, but rather upon the vivacity of the com- 

 bustion. By combining these two observations, he invented a lamp 

 with several parallel wicks, the flames of which mutually exciting each 

 other, without allowing any of the rays to be lost, are capable of pro- 

 ducing an unlimited mass of light. It is said that when it was light- 

 ed at Auteuil, it so dazzled the lamp-maker who had constructed il, 

 that the poor man was unable to find his way home, and was obliged 

 to pass the night in the wood of Boulogne. 



I deem it superfluous to mention how he varied and adapted to all 

 sorts of uses the diflisrent instruments that are employed for lighting. 



