"To the right honorable the Master, Wardens, and elder brethren of the trinity house. This chart of the entrances to the River Thames is most respectfully dedicated by their humble servant William Heather" Nautical chart of the entrance to the River Thames, includes sounding depths, anchorages, buoys, lights, currents, and descriptions of the seabed. Inset: Continuation of the River Thames from Erith to London