County Down Pattern. I wonder what distinguished this from, say, the Country Antrim? Integrity and strength? Or slots large enough to permit disposal of spent pill-packets, perhaps.

Houston_Hamilton_County_Down_Drain_2017-05-10.JPEG

Houston & Hamilton Belfast Foundry 1896. Their main business was spinning-works ironmongery so these grates seem to have been a rather easier sideline.

Robert Street, Newtownards