through whose wards the said watercourse runs, shall inquire if any person dwelling along the said course has a stable or other house, whereby dung or other filth may fall into the same; or otherwise throws therein such manner of filth by which the said watercourse is stopped up, and they (the Aldermen) shall pursue all such offenders. But it shall be lawful for those persons who have houses on the said stream to have latrines over it, provided they do not throw rubbish or other refuse through the same ... and every person having such latrines shall pay yearly to the Chamberlain two shillings for each of them.’ With such arrangements, and the constant increase of buildings on the brook, and the decrease of water supplied to it by the springs in Moorfields, which were gradually being laid dry, the Wallbrook, from a clear stream, became a foul ditch, an open sewer, so that it was found necessary to convert it into a covered one in reality. The brook was filled up with all kinds of debris and partially bricked over, so that when Stow wrote (in 1598) he was obliged to say: ’This watercourse ... was afterwards vaulted over with brick, and paved level with the streets and lanes ... and since that houses also have been built thereon, so that the course of Wallbrook is now hidden underground, and thereby hardly known.’ The stream was covered in at least three centuries before the covering in of the Fleet river, but its course can still be traced by the many important buildings which lined its banks. Commencing at its influx to the Thames, there were along its course on the western side the halls of the Innholders, the Dyers, the Joiners, the Skinners, the Tallow-chandlers, and the Cutlers; the churches of St. John, St. Michael, St. Stephen (which originally stood on the western side), St. Mildred, and St. Margaret; also the Grocers’ and the Founders’ Halls, the estates of the Drapers and Leathersellers, and in Bucklersbury Cornet’s Tower, a strong stone tower which was erected by Edward III. as his ’Exchange of money there to be kept.’ In the sixteenth century it seems to have come into the possession of one Buckle, a grocer, who intended to erect in its place a ’goodly frame of timber,’ but, ’greedily labouring to pull down the tower,’ a part thereof fell upon and killed him.