well, his web page doesn't help much...
http://eisv01.lancs.ac.uk/staff/david/david.htm
but you can get from there to their phone directory
>BARTON DAVID DR. 93038 LINGUISTICS
>
>The University number is 01524 65201
>
>International callers should dial +44 1524 65201
>replacing the + with your international dialing code.
>
>In either case an operator will answer your call and ask for the extension
>you require.
and postal address
>Department of Linguistics and
>M.E.L.,
>Bowland College,
>Lancaster University,
>Lancaster LA1 4YT
>United Kingdom