Secrets of the Selden Map - Map of China: Decoding the Secrets of a Vanished Cartographer - page 150

ket, Net, House, Rooftop, Wall, Well, Horn, Wing, Tail, Ghost, Star, plus a few
more besides. Chinese familiar with the night sky will recognise this vocabulary
list, forthese are the names ofsome ofthe lunar mansions into which the night sky
is divided. There are twenty-eight of them, designated in relation to the movement
ofthemoonaroundtheearth.Sowhataretheydoingonthismap,whentheirprop-
erlocationsareupinthesky,notdownontheearth?Theyarethereonthestrength
of the Chinese cosmological understanding that a common field of energy, or qi ,
binds heaven and earth together. According to this theory, every place in heaven
has a corresponding location on earth, or at least in China. These have been or-
ganised into a system of astral correspondences known as Field Division ( fenye ).
The system dates back two millennia before this map was drawn, although by the
Ming no one really understood how the whole thing worked. People knew the cor-
respondence was there; they just couldn't explain it.
Not knowing what to do with this feature of the Selden map, I did as I usually
do:IturnedtomystandardMingreferencework,ZhangHuang's Documentarium .
As I flipped through the encyclopaedia looking for help, I discovered that the sec-
tionbeforegeographywasaboutcosmologyandincludedanentirechapterdevoted
to Field Division. Even Zhang had difficulty making sense of the system, so he
composed his own treatise on the subject here. 'Study of the Order of Correspond-
ing Constellations among which are Divided the Prefectures and Counties of the
Realm' takes the reader through both general principles and antiquarian sources,
showing how qi works to keep heaven and earth in sync. John Selden would have
appreciated the exercise. It is just the sort of historical exploration of sources and
interpretations that he enjoyed. Ultimately,though, Zhang fails. While he is able to
show how the lunar mansions operate like a universal clock whose hand at noon is
the angle of the sun at the winter solstice, he can't make sense of Field Division.
But Zhang Huang did not disappoint me after all. After reading his essay, I
stumbled upon what I really needed: a map of China displaying regional corres-
pondences to the twenty-eight lunar mansions. This discovery sent me rooting
around in other popular encyclopedias. I found Zhang's prototype in the most
widely reprinted household almanac of the era, The Complete Source for a Myriad
Practical Uses ( Wanyong Zhengzong ), produced by Fujian's most indefatigable
commercialpublisher,YuXiangdou,in1599.Yu'smapisentitled A General Topo-
graphical Map by Province of the Divisions and Correspondences of the Twenty-
Eight Lunar Mansions of the Ming Dynasty .ItisnotaperfectmatchwiththeChina
portion of the Selden map, but it displays most of the astral correspondences and