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, the Sun transits this area on average between June 22 and July 22, and under the sidereal zodiac, the Sun transits this area between approximately July 16 and August 15. In astrology, Cancer is the Cardinal sign of the Water Trigon, which is made up of Cancer, Pisces, and Scorpio. It is considered a negative sign, whose domicile, or ruling planet, is the Moon.