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.
Under the tropical zodiac, Sun transits this area on average between (northern autumnal equinox) September 23 and October 22, and under the sidereal zodiac, the sun currently transits the constellation of Libra from approximately October 16 to November 17.