Stephen Osborn wrote:
I am still not convinced you will find a natural cliff that is *truly*
vertical (e.g. measured by a plumb line) for more than 10 metres, in
order to have the contour lines coincident.

I would be fascinated if you can think of an example where this is
true.

http://www.climbvertigo.ca/location-first-face.htm seems to indicate that in
places, the cliff is actually overhanging.

Tim (tm)
--
tim at economic-truth.co.uk Xbox Live gamertag: Xexyz
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