Kelvinbank, a Caledonian Railway project.

Lovely! Was it tiling or were they perhaps glazed bricks?

I think tiles. The evidence for this is a photo by Stuart Rankin of Partick West from which examples of the green and orange tiles used there were recovered. Also John Paton in his articles for "The true Line " also described them as tiles. 

 

I think glazed brick came into use a bit later. Certainly most Glasgow buildings from the 1890s use tiles on a sand and cement render over ordinary brick. In terms of size they are about 8 inches long, a bit smaller than a glazed brick. Much is still in evidence, numerous closes in west end tenements ( known as a wally close round here ) employ that technique and many are still in a good state today. They tend to be sheltered from direct sunlight and the original colours are well preserved, thats how I acquired the master photos for those. 

Window frames look good too Dave.