"John Rowland" wrote in
message ...

In Thames Rd aka Strand On The Green, just west of the railway
bridge is an alley called Post Office Alley which contains a
small old floodgate at the river end. Set into one wall of this
alleyway is a line of solid metal knobs which are shaped like
carpentry dovetails. The line is level (i.e. level with a
spirit level rather than level with the rather sloping ground).
There is nothing in the other side of the alley. I presume they
serve some flood defence purpose but I can't figure it out. Any
clues?

Photograph he

http://americangrey.co.uk/index.php?showimage=489

It looks to me like they may just have been some sort of fixing
for shuttering when the render was applied to the brickwork - but
why is the rendering higher on that wall than the opposite wall?
Either that, or there's a mezzanine floor inside the building,
and the dovetail joints are exactly that!

--
MatSav