The Ancient Egyptians used simple sundials and divided days into smaller parts, and it has been suggested that as early as 1,500BC, they divided the interval between sunrise and sunset into 12 parts. ... Known as a clepsydra, it uses a flow of water to measure time.
Digesting of food because stomaci acid reaction makes things melt w/ enzymes
Combustion reaction occurs when organic compound reacts with oxygen to form CO₂, H₂O and energy
C(s) + O₂(g) → CO₂(g) is Synthesis reaction not combustion
2 H₂(g) + O₂(g) → 2 H₂O(g) also Synthesis reaction and not combustion
C₃H₈(g) + 5 O₂ → 3 CO₂(g) + 4 H₂O(g) is considered as Combustion reaction
2 C₃H₇OH(l) + 9 O₂(g) → 6 CO₂(g) + 8 H₂O(g) Combustion reaction
because of the metling point of metals, it is difficult to just simply put metal together and have them to stay together without any type of glue or epoxy based creams.
wielding is used to melt the surface or even change the compound completely so they are able to combine with other metals.
same thing with atoms, you need a lot of heat, and speed to simply make salt or even copper because of the elements not really being favorable of each other.