Mechanical Clock: the whole path

1
Tools & MakingI
Stone Tools
The first cutting edge
3.3 Mya
2
Fire & ShelterI
Control of Fire
Light, heat and cooked food
1 Mya
3
Materials & ChemistryII
Pottery
Clay turned to stone by fire
18,000 years ago
needs 2
4
Materials & ChemistryII
Charcoal
Wood cooked slowly under earth
c. 4,500 BCE
needs 1, 2
5
Materials & ChemistryIII
Bronze
Copper and tin, harder together
c. 3,300 BCE
needs 2, 3, 4
6
Materials & ChemistryIII
Iron Smelting
Wider adoption around 1200 BCE; ore, charcoal and a bloomery
c. 1,200 BCE
needs 4, 5
7
MechanicsIII
Gears
Teeth that trade speed for force
c. 300 BCE
needs 5
8
Time & MeasurementIII
Mechanical Clock
Time cut into equal beats
c. 1300
Goal · needs 6, 7