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mapping was not the primary concern of Chinese mapmakers, although they cer-
tainlyunderstooditsprinciples'.Hemadethiscommenttotryandaccountforwhy
Chinesecartography,despiteitstechnicalcapacities,seemedindifferenttotechnic-
al accuracy. Now that we have the Selden map, no such apology is necessary. Here
isscalemappingthatistheequalofthebestworkbeingdoneinEuropeatthetime.
Between Speed and Selden, one gets some parts better than the other, but over all
it is an even draw. What explains this?
The answer is simple, but getting there will be a bit complicated. Start with the
technical problem attendant on the task of drawing a map of a large region. This
can't be done without prior work. To compress vast distances into a small space
you have to have an image already of what the larger region should look like. It is
mucheasiertodrawtheoutlineofabaythantheoutlineofanoceanwhenthemost
you can see is the bay. Before you draw an entire ocean, you need to know what
it looks like, and that you get not from your own experience but from a map you
have already seen.
If the visual accuracy of the Selden map had to come from somewhere, where
was that? We have already speculated that the compass rose and ruler point to ex-
posure to a European map. It doesn't take much casting about to realise that one
waytheSeldencartographerwasabletoproducesuchacoherentandaccuratemap
of the region was by copying a European map. The prototype could not have been
Speed's, which post-dated it, but isn't it possible that he had seen a slightly earli-
er European map of East Asia and copied that? For a long time I resisted coming
to the conclusion that the Selden cartographer had seen a European map before he
drewhisown.Hismapstruckme,andstillstrikesme,asawonderfullyuniqueand
brilliant solution to the challenge of mapping the maritime zones around China. I
didn't want it to be just a copy of a European map, and was able to hold out be-
cause I could never find the map he might have copied. But I couldn't hold out for
ever. Chinese drew East Asia one way, Europeans drew it another, and here was a
Chinese drawing it the European way. I could no longer deny the possibility that
the spatial organisation of the Selden map may have been suggested by his having
seen a European map.
Buthowmuchdoesthatexposureactually matter whentheSelden cartographer
gives no sign of having learned the technical methods by which Europeans meas-
ured and mapped the surface of the earth? The particular strength of European
mapswastheirimpositionofauniformscalethroughtheuseoflatitudeandlongit-
ude.Ourcartographerdidnothaveaccesstothismatrix.Thevariabilityofscaleon
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