One bushel of small coal or sawdust, or both mixed together, two
bushels of sand, one bushel and a half of clay. Let these be mixed
together with common water, like ordinary mortar; the more they are
stirred and mixed together the better; then make them into balls, or,
with a small mould, in the shape of bricks, pile them in a dry place,
and use when hard and sufficiently dry. A fire cannot be lighted with
them, but when the fire is lighted, put two or three on behind with
some coals in front, and the fire will be found to last longer than if
made up in the ordinary way.