The building you are in is in fact Victorian, but only just. Queen Victoria was crowned in 1837 and the Bishop Mill was completed in 1839. It was built for a Mr. William Wilson. Originally there would have been a wheel and a mill lade, long since gone, although you may well still be able to see signs of them.
The use of this site for milling goes back to medieval times. The archbishops of Glasgow had a summer residence in the area. The archbishopric also had a monopoly on milling rights and would have owned and operated the mill which stood there. Obviously those rights disappeared after the Reformation but the name "Bishop Mill" has remained through the centuries.