I managed to knock off a reasonable chunk of the roads I had left to walk around the University at the north-eastern extremity of my mile on this nice sunny walk. As well as being impressed by the number of big townhouses now occupied by various departments, I took some time on my way there to check out a war memorial, and some time on the way back to do a little extra wandering of Berkeley Square.
I've mentioned Sarah Guppy a few times; Thomas Richard was her son. Engineer's Walk has a page on him.
I'm not sure I've ever been through the Severn Tunnel. I should probably try it at some point, just for the experience.