Surrounded by the Fu Hsi Arrangement of the trigrams. The Heng hexagram, true persistence is a process of constant renewal. Symbolic variations include "persevering", "duration" and "constancy". Formed by the trigrams thunder over wind. The upper trigram is Kan and lower trigram is Sun. The image here is of rolling thunder and gentle blowing wind. Heng is telling you that the only sure constant in life is change. The ancient Chinese saw duration as being a very dynamic quality.