It is easy to be overwhelmed by the spectacular grandeur of the Forbidden City, but it is difficult to detect the minutely coded symbolisms hidden everywhere in this vast complex, or to appreciate the exquisite finesse and virtuosity with which it was built.

A recently published book titled, "The Meaning of Details - An Analysis of the Architectural Details of the Forbidden City" (Jubu de yiwei - zijincheng jianzhu jubu jiexi), is a handy manual to guide visitors on a revealing tour around the great architectural masterpiece.

Published by Writers' Publishing House, the book is the fruit of cooperation between Zhang Shuxian, a researcher working with the Ancient Architects Department of the Palace Museum, and Hai Jun, an experienced photographer and editor working with the Writers' Publishing House.

"We have been wanting to publish such a book for a long time," explained Hai Jun, 42, who is both editor and photographer of the book.

"In China, it is often the case that if readers hope to acquire some knowledge about ancient architectural culture, they have to constantly keep up with articles that appear in academic periodicals featuring difficult jargon and tricky language.

"So we wanted something that everyday lovers of ancient architecture could easily approach," said Hai.

In the book, Zhang explains the basic grammar of the Forbidden City's architectural language in a lucid and plain manner. In a sense, the book is a scholarly thesis rendered in a popular way. For any interested layperson, it serves as a highly informative and accessible introductory book.

"Writing the book was an unforgettable experience for me," recalled Zhang, born in 1965 and now a doctorate student of archaeology and museology at Tianjin-based Nankai University.

"In order to satisfy Hai Jun's demands to make things easily accessible, I revised the manuscript four times," said Zhang.

Zhang divided the book into dozens of chapters, each centred on a specific architectural element. On every page there are nicely shot photos to illustrate the issues discussed.

"Taking those photos was one of the most pleasant experiences for me," said Hai.

"When we were working on the book, Zhang led me around the Forbidden City, telling me what to shoot and chatting with me about the amazing expertise and deeply buried stories involved in the smallest possible architectural ingredient of the wonderful palace."

The less-than-200-page book is densely concentrated, full of interesting details.

Apart from practical functions and aesthetic consideration, almost every part of the Forbidden City was designed to carry a certain political or cultural message.

The first and foremost concern was class and rank. Everything was meticulously discriminated to show hierarchical order. Roofs, doors, windows, and ceilings were developed to suit the different ranks of imperial buildings.

Some styles could only be used on the palaces and residences of the royal clan, or special buildings, such as temples.

When He Shen, the notorious corrupt minister of Emperor Qianlong (1736-1795), was brought down from the peak of his power, one of the charges against him was that he had adorned his house with architectural forms that were only allowed on royal palaces.

One of the charges was the use of a special door called "pilumao men," which was a door with a complicated carving and topped by a painted cap-like structure. Today, such a door can be seen inside many of the Forbidden City's palaces.

Statuettes were also made distinct by size and number of architectural components.

The big golden pegs studded on gates for decoration is an example.

On the gate of a palace the number of pegs is 81. It is 49 for a prince's residence, and 25 for the houses of any other sons of emperors.

Another instance is the number of mythical beasts crouching on the roof ridges of palaces. There are 10 on each roof ridge of the Hall of Supreme Harmony (Taihe Dian), but only nine on Palace of Heavenly Purity (Qianqing Gong), seven for Palace of Earthly Tranquility (Kunning Gong), and five for each one of the 12 halls located down the two flanks of the Forbidden City.

The book also tells people how the Forbidden City embodies traditional Chinese philosophies.

One is the philosophy of five elements, which in ancient China people used to explain the way things in the universe interplay and evolve.

Examples of this are the dwellings for descendants of the royal family. The South Three Halls of the Forbidden City were covered by green glazed tiles instead of yellow ones which dominate most other buildings. That is because according to the theory of five elements, green is the colour of wood, the element demonstrating the force of growth, the rising sun, and the bountiful spring.

As the geographical centre of imperial China, the Forbidden City was also carefully designed to follow the theory of feng shui, the traditional Chinese geomancy. The doctrine stipulates that geographical features affect the fortunes of a house.

To acquire the best advantages from feng shui, a hill was built behind the northern wall of the Forbidden City, and two parallel rivers, running west to east, were dug.

According to feng shui theory, a house is best located with a mountain behind it with water in front. The original environment did not satisfy, so emperors used human labour to achieve feng shui perfection.

The construction of the Forbidden City represents the peak of traditional Chinese architecture. In the book, Zhang reveals some astonishing facts that demonstrate the extraordinary finesse of the architectural art.

One vivid example is that the gold foil used to wrap the wooden pillars inside the palaces is so thin that, legend has it, the foil made out of one liang of gold (about 31 grams) could cover 1.3 mu of land (0.09 hectare), and if a piece of the gold foil slipped down from the pillar, it would float in calm air like gossamer.

As so often demonstrated by China's cultural legacy, the Forbidden City is a marvel built by unimaginable human persistence.

The transporting of a 300-ton marble slab, used in the middle of the stairway leading out of the back of Hall of Preserving Harmony (Baohe Dian), is a stunning example of this perseverance.

"To heave such a giant stone from a quarry, and then carry it about 100 li (50 kilometres) into the Forbidden City, demanded the labours of at least 10,000 workers," said the author.

According to legend, the marble slab was transported in the deepest winter. Workers first dug a well each li (half kilometre) along the path. Then they splashed water on the surface of the road which turned to ice, making it smooth for the giant boat that carried the stone.

"To move the boat they used about 1,000 mules and horses, which lead to a line of animals more than one li long," the book reads. "In order to move the animals at the same time, dozens of people struck gongs and drums to orchestrate their work."

For all the symbolic and ornamental concerns that are evident everywhere in the Forbidden City, as Zhang constantly points out in the book, each architectural piece, however small and seemingly superfluous, turns out to have its indispensable practical function.

"It is amazing to know how scientifically and ingeniously these things were devised by the ancient craftsmen, who always made practical function a priority," Zhang remarks in the book.

But Zhang also observes that the simple, curt, natural, but very imposing architectural style developed in the Ming Dynasty (1368-1644) was greatly weakened during the Qing Dynasty (1644-1911), as a fad for ornamental, rococo fashion took root.

The fashion peaked during the reign of Emperor Qianlong, when he had the Forbidden City renovated and many new palaces built.

(China Daily December 24, 2004)