4th period: Barrett / Bosacker

Main

1766 BC - 1122 BC
1046 BC - 256 BC
249 BC - 221 BC
221 BC - 206 BC
206 BC - 220 AD
256 - 221

Inventions

1900 BC
1600 BC
1050 BC
1044 BC
771 BC
500 BC
200 BC
22 BC
105 AD
593 AD