Ch’i flows through the earth like an underground stream that varies its course according to the seasons and to changes made by nature or man to the surface of the Earth. The underground streams that can be observed during caving expeditions are not the same as the channels that carry ch’i.
A parallel can be drawn with the flow of ch’i through the acupuncture meridians of the body. These meridians are not the same as the blood vessels that can be dissected by the surgeon’s knife, but convey life energy through their own specific and precisely locatable channels.
Nevertheless the effectiveness of acupuncture has been admirably demonstrated to the satisfaction of Western medical practitioners on numerous occasions. According to the
practitioners of acupuncture, their work relies upon locating these, as yet undetected, meridians and modifying the flow of ch’i through them.
To complete the parallel, the practitioners of feng shui manipulate the surface of the body of the Earth, and the positioning of buildings, ponds, and so on, to influence the flow of Ch’i.
Source: Feng Shui The Living Earth Manual page 13 Dr Stephen Skinner