ge ▁gold , ▁co pper , ▁silver , ▁and ▁lead ▁native ▁met als ▁found ▁in ▁relatively ▁pure ▁form ▁in ▁nature . ▁The ▁advantages ▁of ▁co pper ▁tools ▁over ▁stone , ▁b one , ▁and ▁wooden ▁tools ▁were ▁quickly ▁apparent ▁to ▁early ▁humans , ▁and ▁native ▁co pper ▁was ▁probably ▁used ▁from ▁near ▁the ▁beginning ▁of ▁Ne ol ith ic ▁times ▁( about ▁ 1 0 ▁ka ). ▁Native ▁co pper ▁does ▁not ▁naturally ▁occur ▁in ▁large ▁amounts , ▁but ▁co pper ▁or es ▁are ▁quite ▁common ▁and ▁some ▁of ▁them ▁produce ▁metal ▁easily ▁when ▁burn ed ▁in ▁wood ▁or ▁char co al ▁fires . ▁Event ually , ▁the ▁working ▁of ▁met als ▁led ▁to ▁the ▁discovery ▁of ▁allo ys ▁such ▁as ▁bronze ▁and ▁br ass ▁( about ▁ 4 0 0 0 ▁B CE ). ▁The ▁first ▁uses ▁of ▁iron ▁allo ys ▁such ▁as ▁steel ▁dates ▁to ▁around ▁ 1 8 0 0 ▁B CE . ▁ ▁Energy ▁and ▁transport ▁ ▁Meanwhile , ▁humans ▁were ▁learning ▁to ▁har ness ▁other ▁forms ▁of ▁energy . ▁The ▁earliest ▁known ▁use ▁of ▁wind ▁power ▁is ▁the ▁sail ing ▁ship ; ▁the ▁earliest ▁record ▁of ▁a ▁ship ▁under ▁sail ▁is ▁that ▁of ▁a ▁N ile ▁boat ▁d ating ▁to ▁the ▁ 8 th - mill en ni um ▁B CE . ▁From ▁pre histor ic ▁times , ▁Egypt ians ▁probably ▁used ▁the ▁power ▁of ▁the ▁annual ▁flo oding ▁of ▁the ▁N ile ▁to ▁ir rig ate ▁their ▁lands , ▁gradually ▁learning ▁to ▁reg ulate ▁much ▁of ▁it