Thanks folks, the plot thickens.
I looked up James in the post office directory (thanks for the link - I'm new at this and hadn't thought to look there). James address is listed as:
Hogg, Jas., Kirkhill Colliery ; ho,
Hayden Villn, Hamilton drive
This is cool, because I suspected he was the manager at the Kirkhill Colliery - would a colliery manager live in such a house? His father was also a colliery manager in Forth, and the home still exists (I have a photo) and it looks to be quite a nice place (for the time, mid-1840's).
Humm....