What to do if you meet a wolf

The BBC are running a series at the moment called In Search of Medieval
Britain, in which an historian is using the Gough map of Britain, drawn
in about 1350, as a guide to travelling the country.

Last night it was the turn of Scotland, still at war with England at
the time the map was drawn.  The map maker probably never travelled
there, and there is little detail shown, and the shape of the coastline
is guessed at:

http://www.bodley.ox.ac.uk/users/nnj/GoughMap_large.jpg

One thing the map does say about Scotland is that "Here there are many
wolves".  Apparently, the medieval bestiary considered the wolf the
beast of the devil.  What you should do if confronted by one was to
take off all your clothes and put them in a pile.  Stand on the pile
and knock two rocks together.  Taking off your clothes reveals your
sins to the animal, and the sound of the rocks summons the Apostles.