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.
Thus no longer are the boundaries of the 12 divisions of the Sidereal zodiac even nominally dependent on any single star with its own proper motion, but rather on A TRULY SIDEREAL MATRIX which encompasses the totality of space. Two important corroborations deserve mention in closing.