Magnetic Compasses and Chinese Architectures
Amelia Carolina Sparavigna
Politecnico di Torino
Abstract: In this paper, we are discussing the effect of the use of magnetic compasses on
the orientation of ancient Chinese architectonical complexes. As Czech researchers proposed
in 2011, assuming these complexes ideally oriented by the ancient architects along north-
south direction, in the case that the surveys were made by means of magnetic compasses,
we can find the axes of the complexes deviating from the cardinal direction, according to the
local magnetic declination that existed at the time the structures were built. Following this
idea, here we discuss some examples of possible alignments obtained by means of magnetic
compasses, concluding that the Chinese surveyors adopted, during the Ming dynasty, a
method based on the magnetic compasses. The architects of the antecedent Yuan Dynasty
probably used an astronomical method.
Keywords: Architectural Planning, Magnetic Compasses, Magnetic Declination, China,
Satellite Images, Google Earth, Yuan Dynasty, Ming Dynasty, Beijing, Forbidden City, Temple
of Heaven, Temples of Earth, Sun and Moon.
An axis exists, known by the Latins as the "axis mundi" (the cosmic axis), about which the
vault of the Heaven seems rotating. This axis, projected on the Earth surface, is giving the
cardinal north-south direction. Some ancient monuments show that this axis was considered
as very important. The Egyptian pyramids of Giza, for instance, were remarkably aligned
along it by the ancient surveyors that used the rising and setting of stars or the shadow of
a gnomon to find the true North [1]. The same is true for the Elamite complex of the Dur
Untash ziggurat that has the directions of the diagonals less than a degree different from
the cardinal directions [2]. Anyway, it is in China that the orientation of building and
monuments according to the “axis mundi” became a rule.
As explained in [3], it was from the Neolithic times that the settlements were oriented along
the north-south direction, in agreement with a solar principle of south-facing entry,
prodromal of the theory of Qi, the vital energy that flows in any living thing, and of the Feng
Shui geomancy. During the Xia and Shang dynasties, the palaces became a symbolic
representation of the cosmos, based on a square layout, oriented strictly north-south, "since
Qi flows that direction" [3]. Today, the north-south orientation is considered one of the
general characteristics of the Chinese imperial urbanism [4], that we can easily see in the
regular subdivision of the urban sites and consequently in the orientation of the buildings.
As we stressed in [5], also Francis John Haverfield (1850-1919), British historian and
archaeologist, noted the regular, cardinally oriented, urban planning of the ancient Chinese
towns. In his book of 1913 [6], he proposed that these towns were laid out in such a manner
according to a very old agrarian system. Actually, the Chinese urban planning is also
including symbolisms concerning cosmology, geomancy, astrology and numerology [3,4], to
have locally the harmony and balance observed in the heavens. And, as we will see in the
following discussion, the Chinese architecture is also linked, in some cases, to the Earth’s
magnet field.
The phenomenon of magnetism was known since ancient times because of the existence of
lodestones. After the observations that oblong objects made of lodestone were attracted by
the poles of the Earth, some methods for determining the direction towards them were