Useless Footnotes I, or Don't Li to Me

Some years ago I read Sunflower Splendour (a collection of Chinese poetry). While it might seem like an odd place to look for technical writing, the editors' footnotes frequently demonstrate how not to provide value to the reader. For instance, place names will often have an accompanying footnote:

So therefore I watched a pool*
Whose clear depths concealed water dragons

*The Coal Valley Pool in the mountains 40 li south of Ch'ang-an.

It's possible that knowing that the name of the pool helps me understand the poem better. It's difficult, however, to understand the value of the knowing that the valley is (a) 40 li away or that (b) the valley is south of Ch'ang-an. Is 40 li close or far away? (This is a tougher question than you might think as my oldest son--who knows somethings about this--tells me that not only has the length of a li has varied over time but, for many periods, the length of a li is unknown. Does the editor mean 40 current li or 40 contemporary li?) Does "south" have connotations that "east" does not?

This is the key point: Knowing that the pool is 40 li south of a city is useless to me unless it contributes to my understanding of the poem. If there are connotations associated with "40 li south" then its those connotations that should be in the footnote. The poem begins in Ch'ang-an so the reference to the city does provide me with some value. But it would mean more if I knew that the pool was easy/hard to get to from Ch'ang-an, a famous spa associated with the city, or....something?

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