c.
From chemical reaction.
a. By direct use of the sun’s rays.
b. From any combustible material.
c. From chemical reaction.
Light does not separately develop power.
Chemical reactions are employed to develop heat, combustion, contraction, or expansion, as means of developing power.
From the foregoing elementary physical sources the following are the practical sources of our power for mechanical purposes.
- Electrical power.
- Magnetic power.
- Tidal motion.
- Falling water.
- Descending weights.
- Wave motion.
- Wind.
- Expansion of air or other gases.
- Steam.
- Explosives.
- Fuels, hydrocarbons, &c.
These are employed in producing power by the following apparatus or motors:—