The Franklin invention most widely known is the Franklin STOVE, a cast-iron STOVE that was designed to be more efficient than traditional fireplaces. It was invented by Benjamin Franklin in 1742 and was the first practical device to improve the efficiency of a fireplace. Another Franklin invention was the lightning rod, which was designed to protect buildings from lightning strikes. The lightning rod was invented in 1752 and was the first successful application of the concept of electrical grounding.