Brass than in brass produced by cementation. These may be "natural alloys" manufactured by smelting zinc rich copper ores in redox conditions. Many have similar tin contents to contemporary bronze artefacts and it is possible that some copper-zinc alloys were accidental and perhaps not even distinguished from copper. However the large number of copper-zinc alloys now known suggests that at least some were deliberately manufactured and many have zinc contents of more than 12% wt which would have resulted in a distinctive golden color. By the 8th–7th century BC Assyrian cuneiform tablets mention the exploitation of the "copper of the mountains"
What the Industrial Revolution Did for Us idea and inventions of the Industrial Revolution that created the features of modern transportation. Cruickshank travels around Britain to introduce the idea and inventions of the Industrial Revolution that created the features of modern medicine. Cruickshank travels around Britain to introduce the idea and inventions of the Industrial Revolution that created the features of modern warfare. Cruickshank travels around Britain to introduce the idea and inventions of the Industrial Revolution that created the features of modern city life. What the Industrial Revolution Did for Us What the Industrial Revolution Did for Us is a BBC documentary series produced in conjunction