A tide mill or tidal mill is worked by harnessing the ebb and flow of the sea. They were situated on tidal river estuaries, away from the waves but near to the sea, and comprised of a mill, outbuildings, a dyke, dam or causeway and millpond beyond. Tide mills date from Saxon times, or even the Roman period. Most are now gone, but some can still be traced today as ruins, scanty remains and earthworks. Some are in use as homes, while in some cases only the millpond survives, often in use as a nature reserve, marina or yacht basin. It is said that Chichester Harbour has the largest concentration of tide mills in the country and at Eling, near Southampton, in Hampshire, a tide mill survives in working order to produce flour today. The old Flood Mill at Deptford was rebuilt as a steam flour mill, where only the Mumfords Mill still stands. That at Faversham became Twymans Mill, which still stands today and is now a block of flats. In Tide Mills of Southern England author Alex Vincent surveys the lost tide mills and their remains in the southern counties of Hampshire, the Isle of Wight, Sussex and Kent, including parts of London that were originally Kent such as Greenwich and Deptford. This fascinating picture of an important but often forgotten part of the industrial heritage of southern England will be of interest to all those who live in this corner of the country or have known it well over the years, as well as those interested in the uses of renewable technology in centuries past.