Yen and Yang are nature's two channels of electric– flows which bring about changes in the Universe. Reference to I –Ching appears in an ancient Chinese Writer's(Fu His) legendary treatise, entitled "I –Ching or Book of Changes "and this is a great gift to human civilization. In that a new system of prediction has been evolved and the system has been explained by establishing coordination between three horizontal unbroken and three broken transverse lines in an octagonal trigram.
Legend has it that a golden yellow Dragon emerged from Logave river and blessed Fu His with these predictive powers. He was a Chinese Emperor. It is certain that the Book existed and was popular before 1100 B.C though it's exact time of writing is not known.
It is believed that Yen and Yang energies flow in a straight line. In I -Ching, Yen is represented by a broken line while Yang is represented by a transverse line. While three lines of Yen and Yang are positioned over each other eight trigrams are formed and each trigram represents an element.
Two sets of trigrams are made, this is 64 diagrams\forms are made by congouring six lines except lines of Yang and yen. which in Chinese parlance is called a hexagram. In I -Ching a result is mentioned in each of the hexagrams and such results pertain to an individual's internal natural strength, character and natural tracts or elements. Those results were formulated by china's Emperor Keng Wen who ruled it around 1160 B.C. After his death his son made certain amendments to it. After some 100 years, the renowned Chinese scholar Confucius made some modifications to the hexagrams after a series of experiments.
In each hexagram coordination between Yen and Yang has been indicated and also conditions keep on changing every second in the Universe and thus changes cast impact on each individual's life. All such beliefs are referred to as 'Taorgin' where an attempt has been made to look into the deep mysteries and changing phenomenon.. Feng shui is just a medium through which they try to comprehend the principles of 'Tao' and Feng Shui devices and instruments help to fully understand natural environments