Ross and his crew with will and muscle somehow survived the force of the tide and current and made it across the river s mouth for the first time. Ross s drama to enter the river was explained by White by using the energy cycle. White explains that lunar energy causes the ocean tide and the sun provides all of the remaining energy of the cycle. The sun heats the atmosphere that heats and evaporates the ocean water and provides the wind to move the moisture to the mountains. The clouds cool and moisture is released as rain or snow that falls to the land.
Gravity pulls the water to the ocean again through the rivers and the process starts over again.
Man attempts to slow down the natural energy cycle to extract energy from the river by building dams. Dams are used to store and regulate water that is used to turn turbines. These turbines power generators that produce electricity. Hydroelectricity was first in abundance. Electricity was a product without much demand.