I've been re reading some 40's detective novels and of course all the police had to use public telephones. If they were working any distance from headquarters they had to make fantastically complicated arrangements to keep in contact and there was great reliance on the emergency announcements on the Home Service (remember those?) "Will Mr & Mrs John Smith believed to be holidaying in the West Country please ring Scotland Yard Whitehall1212". I can barely manage to put the dustbin out without taking my mobile - heaven knows how we'd cope if it all stopped tomorrow!