This view in steep perspective is from the upper level of the marquee erected over the coffer-dam around the site of the southernmost pier of the new London Bridge, for the foundation stone ceremony held on the riverbed on 15 June 1825. There are indications of crowds of spectators around the central arena, focusing on the block and tackle supporting the stone which was lowered into place.
This is one of a sequence of hurried sketches, apparently made in the course of the ceremony, working backwards through the book between folios 78 verso (D18818) and 71 verso (D18804). The event and other studies relating to it at the beginning and end of this sketchbook are discussed in the Introduction.
A tear to the outer edge towards the bottom left has been repaired.