considered almost as old as soy paste — a type of fermented paste (Jiang, 酱) obtained from soybeans — which had appeared during the Western Han dynasty and was listed in the bamboo slips found in the archaeological site Mawangdui. Steel made from cast iron through oxygenation: The earliest known production of steel is a piece of ironware excavated from an archaeological site in Anatolia (Kaman-Kalehoyuk) and is about 4,000 years old. Other ancient steel comes from East Africa, dating back to 1400 BC. In the 4th century BC steel weapons like the Falcata were produced in the Iberian Peninsula, while Noric steel was used by the Roman military. The Chinese, who had been producing cast iron from the late Spring and Autumn period (722–481 BC), produced steel by the 2nd century BC through a process of decarburization, i.e. using bellows to pump large amounts of oxygen on to molten cast iron. This was first described in the Han Dynasty (202 BC – 220 AD) book Huainanzi, compiled by scholars under Prince Liu An (179–122 BC). For steel, they used both quenching (i.e. rapid cooling) and tempering (i.e. slow cooling) methods of heat treatment. Much later, the American inventor William Kelly (1811–1888) brought four Chinese metallurgists to Eddyville, Kentucky in 1845, whose expertise in steelmaking influenced his ideas about air injection to reduce carbon content of iron; his invention anticipated the Bessemer process of English inventor Henry Bessemer (1813–1898). Stinkpot: The stinkpot was an earthenware incendiary weapon part filled with sulphur, gunpowder, nails, and shot, while the other part was filled with noxious materials designed to emanate a highly unpleasant and suffocating smell to its enemies when ignited. The weapon was used in the 19th century during the Qing Dynasty, where the British Admiral Sir William Robert Kennedy recorded the use of the stinkpot in 1856 during the Second Opium War in his book Hurrah for the Life of a Sailor – Fifty Years in the Royal Navy. These incendiary weapons were wrapped in calico bags and were then hoisted in a basket to the truck of the mast. When an enemy ship was alongside, one of the crew members would climb up the mast and primed the stinkpots with lighted joss sticks. The stinkpots were then launched onto the enemy deck by cutting the rope by which the basket had been hoisted. The ensuing noise, flying debris, and pungent