"On Holy Thursday, according to triennial custom, the parochial officers of Battersea, accompanied by a large number of boys taken from the various schools, perambulated the bounds of the parish.
"The muster took place in Battersea-square, about nine o'clock in the morning; and after the boys were formed in procession, with white wands, the parochial officers and others proceeded along the water's edge to Battersea-bridge, and from thence along the river to the Railway Dock, at Nine Elms..."
The perambulation shown on the contemporary Stanford's 6-inch Library map of 1862. It starts and ends at Battersea Square, near St Mary's, the parish church.
I am annotating this account - here's what I have written so far. But do get in touch in the meanwhile if you want to know more, or make a comment.