Elevation and Section of the New Wharfing next the Sluice, showing the part carried away at the last Shaw at Purfleet
Medium: Ink on paper
Plan of the sluice at Purfleet in Essex. A new gunpowder magazine was built on this site in the mid 18th century. Water mills had stood here on the Marr Ditch (now known as the Mardyke) but these had the effect of letting salt water from the river seep into the land. This was thought to be detrimental to the land and so the mills were taken down and new sluices were built as a more efficient drainage system. Wooden floodgates were built to protect the fort from the danger of flooding from the River Thames.