Many watercourses ran from the north into the Thames, the names of which are still attached to districts or streets in the Metropolitan area. Thus, beginning at the East, one has to mention _Langbourn_, a watercourse flowing through what is now Langbourne Ward in the City, taking its course from Aldgate along Fenchurch Street, and probably flowing into the _Wall Brook_, a stream which divided the city into nearly equal halves, and flowed from Moorgate to Dowgate, through the Bank of England and the Poultry, and the name of which still remains in a ward and a street. The river _Fleet_ rose by Highgate Ponds, and meandered through St. Pancras to King’s Cross, where is “Battle Bridge;” thence its course skirted the western side of Clerkenwell, and, flowing at the foot of Saffron Hill, Snow Hill, Holborn Hill, and Ludgate Hill, reached the Thames at Blackfriars. Farther west was _Tybourne_, which rose at Hampstead and flowed through what is now the ornamental water in the Regent’s Park. Then becoming locally known as the Marybourne, its name was associated with the village of Marylebone; it then took the circuitous course of what is now Marylebone Lane, crossed Oxford Street opposite the end of Davies Street, crossed Brook Street, which was named from this fact, then flowed at the back of Bond Street to Bruton Street. In Bruton Street is a curious circuitous mews, which marks its course, running to the south-east corner of Berkeley Square, whence the Tybourne struck west, dividing Devonshire House from Lansdowne House, where now there is a sunken passage between the garden walls. Thence it reached Piccadilly at its lowest point, and flowed through the Green Park to Buckingham Palace. Here it divided, and reached the Thames near Vauxhall Bridge to the west, and near Westminster Bridge to the east, a smaller delta formed by the eastward branch forming Thorney Island, associated with the palace of Edward the Confessor and the monks of St. Peter’s Abbey. The _Westbourne_ also rose at the foot of the Northern Hills, flowed through Kilburn and Bayswater, both suggestive names, through the Serpentine to Knightsbridge, another suggestive name, and so to the Thames at Chelsea Bridge, apparently forming by its course the western boundary of the Grosvenor Estate. These watercourses have all disappeared, because in this Christian country there is no respect for the purity of pure water. They became so swinishly filthy, that for very shame we have covered them up, and when the time arrives for covering up the Thames, which we are so systematically fouling in the same way, I have no doubt that our engineers will be equal to the task.