Londonist have an old photo of these balusters showing the purpose of the horizontal grove in their sides. When first installed here the balusters formed the actual sides of a bench, with a long wooden seat, rather than merely flanking a free-standing, generic bench.
We can find no images of stones from Rennie's London Bridge (now in Arizona) with exactly this shape of baluster, engaged as it is to the wall behind. But the free-standing balusters in Arizona (Londonist have a good picture) are very similar, with just the footing showing some differences. However the balusters of Waterloo Bridge are also the same shape and, importantly, they have the same footing. So, in the absence of any other evidence, we'd say the balusters are from Waterloo Bridge and not London Bridge.
Building London think they are from London Bridge, pointing out that "the Portland Limestone is a match!"
Site: Myddelton House Gardens - Roy and Bridge stones (2 memorials)
EN2, Bulls Cross, Myddelton House Gardens
These are the gardens around Myddelton House. In 1968 the house and the gardens were sold to the Lee Valley Regional Park Authority, who use it as their headquarters. This explains the presence of the memorial to the Chair of that organisation.
