sancti,
Thanks for your quick reply. ...I had actually looked in on that site this morning when I was having a search for information about Barnhill. From the map there, it looks as though it might be Petershill Road, but it isn't clear.
The thing is that I tried an address search for Petershill Road this morning, and there seems to be hundreds of houses in that road, so I might be searching a long time and it might not be there. Still, I might try it.
I remember about forty years ago, I walked right along Peterhill Road looking for work, and it was an enormously long road then.
I think Barnhill later took the name Foresthall, if I remember correctly, and so you would think it might be situated in Foresthall Drive. I am going to have another search.
The 1881 census, which appears on the site you gave in your post, doesn't state the address at the top, so it is a bit of a let down.