The Autobiography of Benjamin Franklin.

Franklin invented an open stove in 1742.

In order of time, I should have mentioned before, that having, in 1742, invented an open stove for the better warming of rooms, and at the same time saving fuel, as the fresh air admitted was warmed in entering, I made a present of the model to Mr. Robert Grace, one of my early friends, who, having an iron-furnace, found the casting of the plates for these stoves a profitable thing, as they were growing in demand.