An account of the new invented Pennsylvanian fire-places : wherein their construction and manner of operation is particularly explained; their advantages above every other method of warming rooms demonstrated; and all objections that have been raised against the use of them, answered and obviated. : With directions for putting them up, and for using them to the best advantage. : And a copper-plate, in which the several parts of the machine are exactly laid down, from a scale of equal parts.