The chapter opens with a description of the formula that is used to determine the time it takes for the sun to rise and set. It is also used to calculate the distance between the sun and the moon. The formula determines the speed with which the sun rises and sets. It also determines the distance from the moon to the equator. The sun rises at a certain time of the day, while the moon at a different time of day. Thus, the formula tells us that the sun will rise in the east, the moon in the west, and the equator at the same time. This means that the moon will rise at a time when the sun is at its brightest and the sun at its darkest. This formula also tells us the time at which the moon and the stars will fall. The chapter ends with the narrator explaining that the formula is not a scientific one, but rather a way for the reader to understand the nature of the sun's movement. The narrator explains that he is using the formula because he wants to use it to find out how fast the moon is moving. He is also using it to determine how long it will take to fall from the sky