"Guiding indicators" indicate the cycle and trend of things. Clement Si Tong first understood the concepts of "cycle" and "trend" because Paul Raymond, vice president in charge of loan business of National Bank of America and Chicago Trust Company, gave him a book "Cycle", which was co-authored by Edward Dewey and Edwin Daley.

Si Tong applied the principles mentioned in this book and achieved remarkable results. For example, when he sees that his company's business is getting more and more dull, he will apply a principle he learned from the book cycle: create new trends with new life, new blood, new methods and new activities.

Later, Si Tong became the chairman of the board of directors of the Bicycle Research Foundation, and Edward Dewey, who founded the Foundation, was the executive director.

Because the study of "cycle" and "trend" is extremely important, but little known, Si Tong asked Mr. Dewey to write an article to explain these two terms in simple sentences.

This is what Mr Dewey calls "circulation".

If you look carefully, you will find that many things often happen repeatedly according to a certain time.

Once the cycle pattern is established, it will continue. In this way, periodic cycle can be a very valuable forecasting tool.

For example, we all know that there is a cycle of 12 months throughout the year. If it is summer now, you will know that it will be cold and snowy in six months. If it is winter now, it can be predicted that you can play tennis and swim in half a year. In doing so, you are using the knowledge of "circulation".

Of course, everyone knows the cycle of seasons, but not everyone knows that there are other cycles.

Anyone who hunts knows that some years have more prey and some years have less prey. But most hunters don't know that the time interval between prey is often fixed, so it is predictable. Hudson's Bay Company knew this cycle and used this knowledge to predict the catch several years ago, so it could make preparations in advance.

Every fisherman knows that the number of fish changes with the seasons. This knowledge can be (and has been) confirmed, and it can be used to calculate the time of fish quantity and accurately predict the catch.

Similarly, volcanologists can use this knowledge to predict volcanic eruptions; Seismologists use this cyclic energy to predict-in a very common way-the coming of earthquakes. The whole scientific field can use periodic knowledge to predict what may happen in the future. Similarly, you can use periodic cycles to predict your mood changes.