Rivers were used to turn watermills and the Romans even used geothermal water for heating. Until the middle of the 18th century renewable sources of energy were the only forms of energy available, but then, with the advent of the Industrial Revolution, fossil fuels began to be exploited.
The Sidereal Zodiac is the position of the sun referenced against the star background, as a measure of the flow of time. The framework for the star background is the constellations the sun passes in front of. This is the one astronomers use.
Just as the effect done from the 13-sign theory effect adopted from sidereal astrology, it might often signify both ends and starts of seasons with cardinal signs might possibly pass one of the places of the fixed sign's signification also in future decades. The four mutable signs of the Zodiac are: 1  Gemini (): marks the end of spring in the northern hemisphere, and autumn in the southern hemisphere.  Virgo (): marks the end of summer in the northern hemisphere, and winter in the southern hemisphere.