A Franklin stove

The Franklin stove (named after its supposed inventor, Benjamin Franklin) is also known as the circulating stove. While Franklin is often credited with its invention, some historians believe the circulating stove was actually invented 70 years prior to Franklin's experimentation with stoves. The metallurgy at the time, however, required that it be made of cast iron, which cracked when fired. This caused smoke to pass through the cracks and into the room: as a result, the original inventors did not patent or sell their device. Franklin designed a similar stove with more advanced metallurgy and was successful in making it work, sometime in 1742, if we are to believe his own account of this invention.

He placed the design in the public domain, as he did with all of his other inventions, and refused offers by others to obtain patents for him. He clearly indicated in his writings his preference in such matters: "... as we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously."

The stove became very popular and gradually replaced open fireplaces. To this day, most fireplaces are box-shaped, similar to the Franklin stove. The exception is the Rumford fireplace, developed by Benjamin Thompson.

While some made bad versions of the original design, others improved it and Franklin himself made a much improved version with better fume extraction and a provision for the use of coal, sometime in the 1770s.

Tales of the origins of the stove mention Franklin's desire to attain a greater degree of domestic comfort, fireplaces having then too many inconveniences. Historians note that at the time Philadelphia, where Franklin lived, was probably one of the biggest cities in North America and that wood was becoming scarce and costly, given the ever rising demand and the fairly poor transportation systems. His stove was described by his contemporaries as giving off twice the amount of heat as a normal fireplace for a third of the wood consumed.