Brickwork.

RASC Hamilton Centre 1979_08
Scanned by Colin Haig 2006-03-25 to 2006-04-08
Scanned with Nikon Coolscan V ED.

These slides, of the construction of the Hamilton Centre Observatory, had a date on the slide mount, 1979 07 Marsh. I am not sure when actually taken or when developed.
Abbreviations: RS - written on slides, likely Robert Speck (aka Bob Speck).

HCO Construction #60