"This difficulty may be in part removed, by supposing... that the heated metal sends off in rays... even when it is not heated red hot; but still, as it never can be admitted that the heat, absorbed by the metal and afterwards thrown off by it in rays, is increased by this operation, nothing can be gained by it; and as much must necessarily be lost... to the air in contact with it, which... always makes its way up the Chimney, and flies off into the atmosphere, the loss of heat attending the use of it is too evident..."