"But, where the fire-place could not be conveniently altered, Savot perforated with small holes a plate of iron, the width and length of which were nearly equal to the hearth, and this was fixed 3 inches above the tiles of the common hearth. On this perforated plate he placed & grill de fer of the same length as the billets to be burned, and raised 9 inches above the plate; the wood was placed on the grate, the charcoal on the perforated plate, and the hearth received the ashes; the air, rising through the small holes, made the charcoal burn briskly, and this so much assisted the burning of the wood, that a rapid draught up the chimney was established, and smoke prevented."