e date and
original purpose of the wooden structures in the Clyde estuary. Nobody,
it is admitted, forged _them_, but on the other hand Dr. Munro, the one
most learned authority on "Lake Dwellings," or "Crannogs," does not think
that the sites were ever occupied by regular "crannogs," or lacustrine
settlements, Lake Dwellings.

VIII--THE ORIGINAL DATE AND PURPOSE OF DUMBUCK AND LANGBANK

The actual structures of Langbank and Dumbuck, then, are confessedly
ancient remains; they are _not_ of the nineteenth century; they are
"unique" in our knowledge, and we ask, what was the purpose of their
constructors, and what is their approximate date?

Dr. Munro quotes and discusses {43} a theory, or a tentative guess of Dr.
David Murray. That scholar writes "River cairns are commonly built on
piled platforms, _and my doubt is_ whether this is not the nature of the
structure in question" (Dumbuck). A river cairn is a solid pile of
stonework, with, perhaps, a pole in the centre. At Dumbuck there is the
central "well" of six feet in diameter. Dr. Murray says that a pole
"carried down to the bottom would probably be sunk in the clay, which
would produce a hole, or well-like cavity similar to that of the Dumbuck
structure." {44}

It is not stated that the poles of river cairns usually demand
accommodation to the extent of six feet of diameter, in the centre of the
solid mass of stones, and, as the Langbank site has no central well, the
tentative conjecture that it was a river cairn is not put forward. Dr.
Murray suggests that the Dumbuck cairn "may have been one of the works of
1556 or 1612," that is, of the modern age of Queen Mary and James VI. The
object of such Corporation cairns "was no doubt to mark the limit of
their jurisdiction, and also to serve as a beacon to vessels coming up
the river."

Now the Corporation, with its jurisdiction and beacons, is purely modern.
In 1758 the Corporation had a "lower cairn, if it did not occupy this
very spot" (Dumbuck) "it stood upon the same line and close to it. There
are, however, no remains of such cairn," says Dr. Murray. He cites no
evidence for the date and expenses of the demolition of the cairn from
any municipal book of accounts.

Now we have to ask (1) Is there any evidence that men in 1556-1758 lived
on the tops of such modern cairns, dating from the reign of Mary Stuart?
(2) If men then lived on the top of a cairn till their food refuse became
"a veritable