I am sorry to announce that I was on a train from Paddington to St Austell just before Christmas and as we travelled through the silver-grey Somerset floods in a leisurely row row row your boat sort of way the guard made this announcement: we are now so late that we have completely lost our path through the network. I remembered that recently they found the remains of a causeway of branches laid thousands of years ago and preserved, as peat is, by the anaerobic conditions in the marshes.