A TREATISE ON GAS-LIGHT.

monly adhered to. This unquestionably re-*duces the value of coals ; because the quantityof radiant heat generated in the combustionof a given quantity of any kind of fuel de-pends much upon the management of thefire, or upon the manner in which the fuel isconsumed. When the fire burns bright, muchradiant heat will be sent off from it; but when

The loss in the use of small coals is more considerable tothe poor, who cannot keep large fires. When they wanttheir breakfast or dinner, the time they can spare is limited;and to have their water sooner boiling, or their meals quickerready; they must make use of the poker, and lose a greatdeal of coal. This fact is so evident, that any body whowishes to make the experiment before recommended, wiltfind that much more bright coal goes to the dust-hole of thepoor man, than to the dust-hole of a rich family, where,the fire-place being large, the small coal has more chanceof burning.

The loss is still greater to the poor, in consequence of theinferior sorts of coal which are sold to them. If it is thelight sort, it burns too quick, and they consume double thequantity ; if the strong sort, it burns too slow, and is nearlyas wasteful; for a great quantity of it then goes to the dust-hole without having been lighted at all.

An incorrect opinion is often entertained, that the realquantity of coal contained in a sack is lessened by separatingor screening the small from the round coals; but we must re-collect, that any compact body occupies less space than isrequired to contain the same matter, reduced to smallerirregular pieces, or to powder.—Now the screening onlytakes away the finest dusty part of the coals, and admitsmore small pieces of round coals to be filled into the sack.