Building Stone

In pursuit of building materials we paid a visit to a local company and discovered this stone, which forms part of their gateway.

Erosion has obscured the letters but this is no ordinary milestone. We think the inscription reads:

5 MILES from the General Post Office EDINBURGH erected to regulate the Post Horse duties Payable by Hackney Coaches 1821

I have adjusted the contrast to bring out the lettering, clearer still in large. When I have time I shall investigate further.