Invented in 1869 by Joab R. Donaldson of Oliphant Furnace, Pennsylvania, USA. The fireplace insert is a device inserted into an existing masonry or prefabricated wood fireplace.
Fireplace inserts are made from cast iron or steel and now have self-cleaning glass doors that allow the flames of the fire to be viewed while the insulated doors remain closed, making the fire more efficient. (courtesy of Wikipedia)
