Continuing improvements led to the furnace and bellows and provided, for the first time, the flexibility to smelt and forge gold, copper, silver, and lead – native metals present in comparatively pure type in nature. The advantages of copper tools over stone, bone and wooden tools were shortly apparent to early humans, and native copper was most likely used from close to the beginning of Neolithic instances . Eventually, the working of metals led to the discovery of alloys such as bronze and brass . The first use of iron alloys similar to metal dates to around 1,800 BCE. Since …