ON EVAPORATING FURNACES. ^Q'5 



glafs Chimney, as an example of the neceffity of ralfing the 



temperature round the combufiible, whenever a compleat and 



powerful combuftion is required. At prefent, I (hall take the 



enameiler's lamp as an example In fupport of my new obferva- 



tions ; I may fay that I am indebted to the examination of its 



efFeds, for thofe which it has led me to make. In fact, if the EfFefts of the 



jet of the flame of an enaraeller's lamp be examined, it will be In'thTfilimt'^ f 



found that the intenfity of its adion depends on the current of Argand'slampj 



air which is dire6led on the flame of the wick ; it will alfo be 



feen, that it is only at the extremity of its jet that the greatefl 



energy of the calorific rays exifts, and that its intenfity is fuch 



that, by means of this lamp, effeds may be produced, which 



are, comparatively, as powerful as thofe obtained in our bed 



furnaces. 



This mode of action of the caloric proves, therefore, that its 

 efFeds may be augmented, by augmenting the rapadity of its 

 current, and by direding it Ikilfully upon the body to be heated.; 

 Thefe are the conditions which I have endeavoured to unite in 

 my new contlrudion, and which, agreeably to the application 

 1 have made of them, are employed to (upport an opinion which 

 required an experiment on a large fcale to efcape being placed 

 in the clafs of hypothefes. 



Having been lately confulted upon the conftru6tion of a applied to works 

 brewer's furnace, I took the opportunity to ftiow the great ad-°"^ ^^""^^ ^^^^^* 

 vantages of the alterations which my obfervations appeared to 

 me to render necefTary, and to induce the proprietor to conftru6t 

 his furnace according to the plan I fent him. 



The following is the refult of the experiments which were Comparlfon of 

 made to afcertain tbe advantages pofTeffed by the new furnace ^^^° ^"rnaces. 

 over that which it replaced, ' . , 



i iThe old furnafce required 2^ hours to raife the temperature 

 of 2300 litres of well- water to 50*^ of Reaumur, and confumed 

 in the operation, which was repeated daily, 625 kilogrammes 

 of new dry wood. 



The prefent furnace, on the contrary, confumes only 450 

 kilogrammes of wood in the fame operation, and is only one 

 hour in raifing the temperature of 2500 litres of well-water 

 to 50*^ : Whence it refults, tliat this new conftrudion evidently 

 makes a faving of fV '" time and nearjy one third in the com- 

 builible. 



Such 



