246 Memoir on the Fabrication of Charcoal, 



It is no doubt to tliis high price of wood, and the neceflity 

 of deriving as much advantage as poflible from the few fo- 

 refts in the neighbourhood, that we are indebted for a 

 method of fiibricating charcoal which fccms to be prao'tifed 

 no where clfe. At any rate, from the filencc refpe6ling it in 

 tlie CoUeclion des Arts et dcs ]\le tiers, and in La Nouvelle 

 Enryc/opedie, and from the furprife exprefl'ed by fcveral pcr- 

 fons on feeing, in the market of Rochellc, pieces of char- 

 coal of fuch a fize and length that thev could be tied up and 

 tranfported in the form of faggots, there is reafon to pre- 

 fume that it is not known. 



The Council of Mines, defirous to colleft every thing that 

 can contribute to the fuccefs of the different eftablifhments 

 of the republic, requeftcd me to make known the procefs. 

 What I have been able to colIe£t on the fubjecl is as fol- 

 lows : 



The charcoal of the foreft of Benon is fold at Rochelle 25 

 or 30 per cent, above the price of everv other charcoal fabri- 

 cated from the fame kind of oak brought from the neigh- 

 bouring departments. The wood of this foreft may have 

 fomc fuperiority over that of others : it grows flowly, is hard 

 and heavy ; but, as it appears that the fame means of fabri- 

 cation are not employed in other places, a fmall part only 

 ot the great ditl'erence in the prices of charcoal can be 

 afcribed to this fuperiority of the wood. 



The care taken to place the furnace in the centre of fur- 

 rounding walls, which, by checking the current of the infe- 

 rior air, renders the operation of charring more uniform and 

 more perfeel, with fome other circumftances which will be 

 mentioned hereafter, feem to contribute in a fpecial manner 

 to the advantage in queftion. 



The heaps of wood which are to be converted into char- 

 coal, are everywhere almoft difperfed throughout the foreds, 

 and remain expofed to the action of the air in every direc- 

 tion ; but at Benon the charcoal is fabricated in chambers. 



Thefe chambers are 20 feet fquare : the walls, built of 

 rough ftones, united by means of earth, are 15 feet in height, 

 and are covered with planks and tiles, arranged in fuch a 

 manner, that between the planks a fpace of two inches is 

 left, to aflbrd a free paffage to the fmoke. 



The floor of the chamber is convex : a mafs of argillaceous 

 earth riles in the centre about fix or fcvai inches, having be- 

 tween it and tiie wall a circular fpace two feet and a half in 

 breadth, and the four corners free for the fervice of the fur- 

 nace. 



The only wood employed is ouk, known under the name 

 6 ' of 



