Some Basics
Since books are very confusing to one trying to figure out Feng Shui (that's how the secrets are kept!), I am going to do a few posts with some basics. I hope that they are helpful to those of you who are interested, but getting confused.
Remember, I practice Classical Feng Shui and use the Flying Stars to analyse the qi within buildings. There are other schools, but the basics should be the same.
In ancient times, the flow of qi (energy) was observed for many, many years and, eventually, charts were created which documented this flow of qi. With a parent's death, the children sought to find the best burial place for the grave (yin house). If the children placed the parent in a particularly fortunate place, then they believed that they would be rewarded for this effort. Later, this study was applied to homes (yang houses) to improve the lives of those people living within them.
It took many, many years for an apprentice to learn FS. And, more often than not, the Master only gave up his secrets near the end of his life. Some did not pass on the information. So, there is a lot of different information available. My teacher does research into the old texts looking for confirmation of material
Qi comes from the mountain, on the wind, toward the water where it gathers and can be used. This mountain is in a different direction each period; the water direction is the auspicious wealth direction and the land should be flat there; there is also a secondary wealth direction for each Period.
So, the energy cycles are each 20 years in length (a Period); three Periods are in each of three larger cycles: Upper, Middle and Lower. That makes 9 cycles of 20 years each = 180 years. Currently, we are in Period 8 which is the middle 20 years of the Lower Cycle.