FARMERS' REGISTER 



659 



pine as 9— and their relative value being hickory 

 100, white pine 42— or the first being considerably 

 more than twice as valuable as the latter. The 

 table which we shall append will exhibit the rela- 

 tive value of the difterent kinds of fuel in com- 

 mon use. 



Charcoal forms a considerable item of fuel ; and 

 the facts which Mr. Bull has given us upon this 

 subject will be found to be new and interesting. 

 The value of charcoal, like that of wood, is prin- 

 cipally to be determined by its weight — a pound 

 Irom one kind of wood aflbrding about as much 

 heat as a pound from another kind. The quanti- 

 ty, or rather weight, of charcoal, afforded by the 

 different kinds of wood, is nearly in proportion to 

 the relative weight of the wood. Thus hickory 

 produces 26,22, the specific gravity of the dry coal 

 being .625 ; while the white pine produces 24.35, 

 and the specific gravity of the dry coal being only 

 .298. Thus, whether burnt in the Ibrm of wood 

 or of charcoal, a cord of hickory affords more than 

 tv/ice the heat that is found in a cord of white 

 pine. The value of charcoal, however, depends 

 much upon the manner in which it is prepared. 

 The more completely the atmospheric air is ex- 

 cluded from the wood, while under the process of 

 being charred and the more heat that is given to 

 it, the heavier, the harder, and the better will be 

 the product. The best charcoal will be found of 

 a elate color on its surfiice, dense, sonorous and 

 brittle; while inferior qualities approach to a jet 

 black, and are solt and powdery, upon the exterior. 

 To obtain the best quality, Mr. Bull recommends 

 that the wood be piled in a single tier, that charcoal 

 dust be interposed between the wood, that the pile 

 be covered with clay, and then a layer of sand, to 

 close the cracks which the fire may cause in the 

 clay, and that the fire be communicated at the ex- 

 terior base, and in ths centre and from the top. 

 An intelligent collier, who partially adopted Mr. 

 Bull's recommendation, gained by it 10 per cent. 

 in quantity by measure, and Mr. B. found the coal 

 nearly 20 per cent, heavier than usual. If these 

 facts are correct, and we have no reason to doubt 

 them, it would be an excelleiit police regulation in 

 our towns, to have charcoal sold by the weight, 

 instead of by measure, and would ultimately be 

 beneficial to the seller as well as to the buyer. 



The loss in weight which wood undergoes in 

 drying, and the moisture which it absorbs, by ex- 

 posure, after it has become dry, are matters of con- 

 siderable interest to the fiirmer and the consumer. 

 Hickory wood cut green, and made absolutely dry, 

 experienced a diminution in its weight of 37| per 

 cent., white oak lost 41 per cent., and sofi maple 48 

 per cent., or very near one-half. Both wood and 

 charcoal, alter being made perleclly dry, absorbed 

 in twelve months, under cover, from 8 to 12 per 

 cent, of moisture. 



It we assume, says Mr. B. the mean quantity 

 of moisture in the woods, when green, at 42 per 

 cent, the great disadvantage of attempting to burn 

 wood in this slate, [or transport it a distance,] 

 must be obvious, as in every 100 lbs, of this com- 

 pound of wood and water, 42 pounds of aqueous 

 matter must be expelled from the wood, [or trans- 

 ported ;] and as the capacity of water lor absorb- 

 ing heat is as 4 to 1, when compared with air, 

 and probably greater during its conversion into 

 vapor, which must be effected before it can escape, 

 the loss of heat must consequently be great. 



