"The use of these fireplaces in very many houses ...is a great saving of wood to the inhabitants."
Benjamin Franklin, statesman and scientist
Before inventing the lightning rod and bifocal lenses, American statesman and polymath Benjamin Franklin (1706-1790) had turned his attention to keeping peoples' homes warm and safe. In the eighteenth century many homes in the United States, built of wood and heated by open hearths, were at great risk of fire. This had concerned Franklin since at least 1735, when he organized the first volunteer fire department in his adopted home town of Philadelphia, Pennsylvania. He also called for building regulations to include minimum safety standards in fireplace design—modern standards are still based on them.
In 1742 he designed a new stove that he called the "Pennsylvania fireplace"; it was later called the "Franklin stove" or "circulating fireplace." The stove was a box lined with metal that stood away from the wall, improving efficiency compared to the standard fireplace where much of the heat was lost to the wall behind it. He also added flat plates or "baffles" at the stove's rear to improve the flow of air. The only flaw, later fixed by Franklin, was that smoke had to escape through the base of the stove, and it filled the room.
The stove was first manufactured by Franklin's friend Robert Grace, but the inventor refused to patent the device in order to keep the technology freely available—a story that is often cited as an early example of open-source development.
The freedom to tinker with Franklin's design was explored in the 1780s by David Rittenhouse, who added an L-shaped chimney. History has preferred to call it the Franklin stove nonetheless, and there are many in use to this day.
