Early instruments and techniques
The history of feng shui covers 3,500+ years before the invention of the magnetic compass. It originated in Chinese astronomy. Some current techniques can be traced to Neolithic China, while others were added later (most notably the Han dynasty, the Tang, the Song, and the Ming).
The astronomical history of feng shui is evident in the development of instruments and techniques. According to the Zhouli, the original feng shui instrument may have been a gnomon. Chinese used circumpolar stars to determine the north-south axis of settlements. This technique explains why Shang palaces at Xiaotun lie 10° east of due north. In some cases, as Paul Wheatley observed, they bisected the angle between the directions of the rising and setting sun to find north. This technique provided the more precise alignments of the Shang walls at Yanshi and Zhengzhou. Rituals for using a feng shui instrument required a diviner to examine current sky phenomena to set the device and adjust their position in relation to the device.
The oldest examples of instruments used for feng shui are liuren astrolabes, also known as shi. These consist of a lacquered, two-sided board with astronomical sightlines. The earliest examples of liuren astrolabes have been unearthed from tombs that date between 278 BC and 209 BC. Along with divination for Da Liu Ren the boards were commonly used to chart the motion of Taiyi through the nine palaces. The markings on a liuren/shi and the first magnetic compasses are virtually identical.
The magnetic compass was invented for feng shui and has been in use since its invention. Traditional feng shui instrumentation consists of the Luopan or the earlier south-pointing spoon (指南針 zhinan zhen)—though a conventional compass could suffice if one understood the differences. A feng shui ruler (a later invention) may also be employed. - Wikipedia