From The Art and Popular Culture Encyclopedia
Feng Shui (風水 - literally, wind and water) is an ancient Chinese proto/ethnoscience that addresses the layout of cities, villages, dwellings, and buildings. It is erroneously identified as geomancy, an unfortunate misnomer courtesy of 19th-century Christian missionaries. The most recent (1980s) definition, heavily flavored by the New Age movement, explains Feng Shui as the arrangement of objects within a home to obtain an optimum flow of qi. In rural China, according to recent fieldwork by Ole Bruun, Feng Shui is used to obtain health, family harmony, and prosperity; qi flow is rarely mentioned.
Feng Shui began as an interplay of construction and astronomy. Early Yangshao houses at Banpo were oriented to catch the midafternoon winter sun at its warmest, just after the solstice. (Some tribes in southern China still refer to this month as "House-building Month.") Professor David Pankenier and his associates performed retrospective computation on the Chinese sky at the time of the Banpo dwellings (4000 BCE) to show that the asterism Yingshi ("Lay out the Hall" in the Warring States period and early Han era) corresponded to the sun's location at this time. Several hundred years earlier the asterism Yingshi was known as Ding. It was used to indicate the appropriate time to build a capital city, according to the Shijing.
The tombs of Shang kings and their consorts at Xiaotun lie on a north-south axis, ten degrees east of due north. The Shang palaces at Erlitou are also on a north-south axis, slightly west of true north. These orientations were obtained by astronomy, not a magnetic compass.
All capital cities of China followed rules of Feng Shui for their design and layout. These rules were codified during the Zhou era in the Kaogong ji, "Manual of Crafts." Rules for builders were codified in the Lu ban jing, "Manual for Carpenters." Graves and tombs also followed rules of Feng Shui. From the earliest records it seems that the rules for these structures were developed from rules for dwellings.
The oldest known Feng Shui device consists of a two-sided board with astronomical sightlines. Liuren astrolabes have been unearthed from Qin-era tombs at Wangjiatai and Zhoujiatai. These devices date between 278 BCE and 209 BCE. Today Feng Shui practitioners can select from three types of Luopan or Feng Shui compasses: San He (the so-called "form school," although the compass name means "Triple Combination"), San Yuan (the so-called "compass school," although the compass name actually refers to time), and the Zong He that combines the other two.
Feng Shui is still considered important in some segments of modern Chinese culture, especially Hong Kong and Taiwan; most educated Chinese in the People's Republic have never heard of it. Those who have often think of it as peasant superstition. Since the mid-20th century it has been illegal in the PRC because of the propensity for fraud. This all came about because of the Cultural Revolution that set about destroying most of the old culture of China. It has been kept alive because the books and masters moved out of mainland China to areas such as Taiwan and Hong Kong.
Traditional or classical Feng Shui always involves the use of a Luopan and iterative mathematics. The New Age versions (Black Sect, Pyramid, Fuzion, "intuitive," etc.) typically do not.