The Open Hearth Process is a method used in steelmaking that involves melting iron and scrap steel in a large, shallow furnace. This process allows for the precise control of the chemical composition of the steel by adding various materials, such as limestone and manganese, to remove impurities. The furnace is heated using a mixture of natural gas and air, which helps achieve the high temperatures needed for melting. Developed in the mid-19th century, the Open Hearth Process was widely used until the late 20th century, when it was largely replaced by more efficient methods like the Basic Oxygen Process. Despite its decline, the Open Hearth Process played a significant role in the industrial revolution, enabling mass production of steel for construction and manufacturing.