Fw: history of the use of ledge symbols in cave maps

[Andy Waddington]

Sometime before sending, Wookey typed
 (and on Friday 2011-03-18 sent):

> I just received this mail looking for historical info on
> ledge symbols. 
 
It would be useful if he sent some graphics as to exactly what
symbols he means. What you are describing (pitch and aven symbols)
is not what I would have thought he meant. Especially as he is
talking about profile views (elevations, I presume, possibly
extended ones ?). I would think he was talking about the little
lines of "T" symbols representing ledges on the walls, although
maybe that is only for ledges used for traversing. I'm sure I
recall seeing symbols meaning "ledge on far wall" and "ledge on
near wall" for use in elevations, but I have no idea where and
can't actually go looking just at the moment...

Steven Craven did a lot of work on early cave cartography, such
as CFD Long :-) Chances are that he is either dead or ... very
old, by now.

Obvious place to start research is in the Cave Research Group,
who invented (or adopted) the cave survey symbols that became
the BCRA ones. I'm pretty sure the NSS library will have all
those, but Huntsville, Alabama's quite a long way away from West
Virginia :-(

Andy