surveying

[graham]

A system like Distributed Proofreaders - http://en.wikipedia.org/wiki/Distributed_Proofreaders - would, I think, work really well for this. I can't imagine they'd be particularly happy about us cavers smuggling archived survey notes into the Project Gutenberg work flow (but then again... you never know... some very dense technical literature has been typed up by them, as well as old phonebooks), but the software is open source and either it, or a similar setup, could be installed to a webserver somewhere.

We're working on it. Watch this space.

Just to comment on the PDFs, they appear to be scanned as 'Black and White'. If they were rescanned as greyscale they'd be more legible.

Agreed. But that's what I had available when that job was done. I have successfully extracted the data for half a dozen or more caves, though.