Metallurgy

• Specific techniques and scientific principles included: excavation and ore identification; separation of ore from non-ore bearing rock; smelting by the use of bellows and heated furnaces; and smithing and further refinement.
• The use of multishaft and open-shaft systems facilitated circulation of air in intense heating processes, while the bellows principle produced strong currents of air in a chamber expanded to draw in or expel air through a valve.
• Products

  (1) armor (as in some northern Nigeriancity-states)

  (2) jewelry (of gold, silver, iron, copper and brass)

  (3)cooking utensils, cloth dyeing, sculpture, and agricultural tools.