But the real surprise comes if you employ the wooden walkway to get
close enough to the culvert to look inside: many of the granite blocks
are recycled stone stringers! These had been used for the initial
(circa 1830) track construction on the Old Main Line. I've marked
with small circles some of the holes where the iron strap rail had been
affixed to the heavy blocks.
In 1830 these blocks had been hewn by hand, and the B&O wasn't one to waste
all that effort. When the stringers proved unacceptable as a track bed on
the OML, the B&O pulled most of them up, and obviously hauled some here.
This is one of only two known bridges/culverts to have been built primarily with the
recycled stringers, but there are likely others waiting to be discovered.
Side note: the built-in flash on my Sony Mavica digital camera rarely
works properly: it seems to be uncoordinated with the opening of the
lens, resulting in uselessly dark photos. This is the only time the
flash has worked. I almost didn't bother trying, but am glad I did.