Today’s walk was a figure of eight advertised as six miles in the morning and four in the afternoon. When I looked at the map three days ago to refresh my memory of the routes I suspected that I’d underestimated the distances. This was confirmed today by my GPS device. My right thumb from tip to metacarpophalangeal joint measures one mile on the OS Explorer map. Usually this is accurate but on today’s walk it was out by 25%. Must try harder.