It was in July 1898, that Mr. Donnelly, who had been prospecting during
two years for antiquities in the Clyde estuary, found at low tide,
certain wooden stumps, projecting out of the mud at low water. On August
16, 1898, Dr. Munro, with Mr. Donnelly, inspected these stumps, "before
excavations were made." {25a} It is not easy to describe concisely the
results of their inspection, and of the excavations which followed. "So
far the facts" (of the site, not of the alleged relics), "though highly
interesting as evidence of the hand of man in the early navigation of the
Clyde basin present nothing very remarkable or important," says Dr.
Munro. {25b}
I shall here quote Dr. Munro's descriptions of what he himself observed
at two visits, of August 16, October 12, 1898, to Dumbuck. For the
present I omit some speculative passages as to the original purpose of
the structure.
"The so-called Dumbuck 'crannog,' that being the most convenient name
under which to describe the submarine wooden structures lately
discovered by Mr. W. A. Donnelly in the estuary of the Clyde, lies
about a mile to the east of the rock of Dumbarton, and about 250 yards
within high-water mark. At every tide its site is covered with water
to a depth of three to eight feet, but at low tide it is left high and
dry for a few hours, so that it was only during these tidal intervals
that the excavations could be conducted.
On the occasion of my first visit to Dumbuck, before excavations were
begun, Mr. Donnelly and I counted twenty-seven piles of oak, some 5 or
8 inches in diameter, cropping up for a few inches through the mud, in
the form of a circle 56 feet in diameter. The area thus enclosed was
occupied with the trunks of small trees laid horizontally close to
each other and directed towards the centre, and so superficial that
portions of them were exposed above the surrounding mud, but all
hollows and interstices were levelled up with sand or mud. The tops
of the piles which projected above the surface of the log-pavement
were considerably worn by the continuous action of the muddy waters
during the ebb and flow of the tides, a fact which suggested the
following remarkable hypothesis: 'Their tops are shaped in an oval,
conical form, meant to make a joint in a socket to erect the
superstructure on.' These words are quoted from a 'Report of a
Conjoint Visit of the Geological and Philosophical Societies to the
Dumbuck Crannog, 8th April, 1899.' {26}
The result of the excavations, so far as I can gather from
observations made during my second visit to the 'crannog,' and the
descriptions and plans published by various societies, may be briefly
stated as follows.
The log-pavement within the circle of piles was the upper of three
similar layers of timbers placed one above the other, the middle layer
having its beams lying transversely to that immediately above and
below it. One of the piles (about 4 feet long) when freshly drawn up,
clearly showed that it had been pointed by a sharp metal implement,
the cutting marks being like those produced by an ordinary axe. The
central portion (about 6 feet in diameter) had no woodwork, and the
circular cavity thus formed, when cleared of fallen stones, showed
indications of having been walled with stones and clay. Surrounding
this walled cavity--the so-called 'well' of the explorers, there was a
kind of coping, in the form of five or six 'raised mounds,' arranged
'rosette fashion,' in regard to which Mr. Donnelly thus writes:
'One feature that strikes me very much in the configuration of the
structure in the centre is those places marked X, fig. 20, around
which I have discovered the presence of soft wood piles 5 inches in
diameter driven into the ground, and bounding the raised stone
arrangement; the stones in these rude circular pavements or cairns are
laid slightly slanting inwards.' {27}
From this description, and especially the 'slanting inwards' of these
'circular pavements' or 'cairns,' it would appear that they formed the
bases for wooden stays to support a great central pole, a suggestion
which, on different grounds, has already been made by Dr. David
Murray.
The surrounding piles were also attached to the horizontal logs by
various ingenious contrivances, such as a fork, a natural bend, an
artificial check, or a mortised hole; and some of the beams were
pinned together by tree-nails, the perforations of which were
unmistakable. This binding together of the wooden structures is a
well-known feature in crannogs, as was demonstrated by my
investigations at Lochlee and elsewhere. {28a} It would be still more
necessary in a substratum of timbers that was intended (as will be
afterwards explained) to bear the weight of a superincumbent cairn.
Underneath the layers of horizontal woodwork some portions of heather,
bracken, and brushwood were detected, and below this came a succession
of thin beds of mud, loam, sand, gravel, and finally the blue clay
which forms the solum of the river valley. {28b} The piles penetrated
this latter, but not deeply, owing to its consistency; and so the blue
clay formed an excellent foundation for a structure whose main object
was resistance to superincumbent pressure.
Outside the circle of piles there was, at a distance of 12 to 14 feet,
another wooden structure in the shape of a broad ring of horizontal
beams and piles which surrounded the central area. The breadth of
this outer ring was 7 feet, and it consisted of some nine rows of
beams running circumferentially. Beyond this lay scattered about some
rough cobble stones, as if they had fallen down from a stone structure
which had been raised over the woodwork. The space intervening
between these wooden structures was filled up in its eastern third
with a refuse heap, consisting of broken and partially burnt bones of
various animals, the shells of edible molluscs, and a quantity of
ashes and charcoal, evidently the debris of human occupancy. On the
north, or landward side, the outer and inner basements of woodwork
appeared to coalesce for 5 or 6 yards, leaving an open space having
stones embedded in the mud and decayed wood, a condition of things
which suggested a rude causeway. When Mr. Donnelly drew my attention
to this, I demurred to its being so characterised owing to its
indefiniteness. At the outer limit of this so-called causeway, and
about 25 feet north-east of the circle of piles, a canoe was
discovered lying in a kind of dock, rudely constructed of side stones
and wooden piling. The canoe measures 35.5 feet long, 4 feet broad,
and 1.5 foot deep. It has a square stern with a movable board, two
grasping holes near the stem, and three round perforations (2 inches
in diameter) in its bottom. On the north-west border of the
log-pavement a massive ladder of oak was found, one end resting on the
margin of the log-pavement and the other projecting obliquely into the
timberless zone between the former and the outer woodwork. It is thus
described in the _Proceedings of the Glasgow Philosophical
Society_:{29}
'Made of a slab of oak which has been split from the tree by wedges
(on one side little has been done to dress the work), it is 15 feet 3
inches long, 2 feet broad, and 3.5 inches thick. Six holes are cut
for steps, 12 inches by 10 inches; the bottom of each is bevelled to
an angle of 60 degrees to make the footing level when the ladder is in
position. On one side those holes show signs of wear by long use.'
An under quern stone, 19 inches in diameter, was found about halfway
between the canoe and the margin of the circle of piles, and
immediately to the east of the so-called causeway already described.
I carefully examined the surface of the log-pavement with the view of
finding evidence as to the possibility of its having been at any time
the habitable area of this strange dwelling-place; but the result was
absolutely negative, as not a single particle of bone or ash was
discovered in any of its chinks. This fact, together with the
impossibility of living on a surface that is submerged every twelve
hours, and the improbability of any land subsidence having taken place
since prehistoric times, or any adequate depression from the shrinkage
of the under-structures themselves, compels me to summarily reject the
theory that the Dumbuck structure in its present form was an ordinary
crannog. The most probable hypothesis, and that which supplies a
reasonable explanation of all the facts, is that the woodwork was the
foundation of a superstructure of stones built sufficiently high to be
above the action of the tides and waves, over which there had been
some kind of dwelling-place. The unique arrangement of the wooden
substructures suggests that the central building was in the form of a
round tower with very thick walls, like the brochs and other forts of
North Britain. The central space was probably occupied with a pole,
firmly fixed at its base in the 'well,' and kept in position by
suitable stays, resting partly on the stone 'cairns' already
described, partly in wooden sockets fixed into the log-pavement, and
partly on the inner wall of the tower. This suggestion seems to me to
be greatly strengthened by the following description of some holed
tree-roots in Mr. Bruce's paper to the Scottish Antiquaries: {30}
'Midway between the centre and the outside piles of the structure what
looked at first to be tree-roots or snags were noticed partly imbedded
in the sand. On being washed of the adhering soil, holes of 12 inches
wide by 25 inches deep were found cut in them at an angle, to all
appearance for the insertion of struts for the support of an upper
structure. On the outside, 14 inches down on either side, holes of 2
inches diameter were found intersecting the central hole, apparently
for the insertion of a wooden key or trenail to retain the struts.
These were found at intervals, and were held in position by stones and
smaller jammers.'
The outer woodwork formed the foundation of another stone structure,
of a horseshoe shape, having the open side to the north or landside of
the tower, which doubtless was intended as a breakwater. By means of
the ladder placed slantingly against the wall of the central stone
building access could be got to the top in all states of the tides.
The people who occupied this watch-tower ground their own corn, and
fared abundantly on beef, mutton, pork, venison, and shell-fish. The
food refuse and other debris were thrown into the space between the
central structure and the breakwater, forming in the course of time a
veritable kitchen-midden.
Besides the causeway on the north side, Mr. Bruce describes 'a belt of
stones, forming a pavement about six feet wide and just awash with the
mud,' extending westwards about twenty yards from the central cavity,
till it intersected the breakwater. {31} These so-called pavements
and causeways were probably formed during the construction of the
tower with its central pole, or perhaps at the time of its demolition,
as it would be manifestly inconvenient to transport stones to or from
such a place, in the midst of so much slush, without first making some
kind of firm pathway. Their present superficial position alone
demonstrates the absurdity of assigning the Dumbuck structures to
Neolithic times, as if the only change effected in the bed of the
Clyde since then would be the deposition of a few inches of mud. At a
little distance to the west of these wooden structures there is the
terminal end of a modern ditch ('the burn' of Mr. Alston), extending
towards the shore, and having on its eastern bank a row of stepping-
stones; a fact which, in my opinion, partly accounts for the
demolition of the stonework, which formerly stood over them. So far,
the facts disclosed by the excavations of the structures at Dumbuck,
though highly interesting as evidence of the hand of man in the early
navigation of the Clyde basin, present nothing very remarkable or
improbable. It is when we come to examine the strange relics which
the occupants of this habitation have left behind them that the real
difficulties begin."
Dr. Munro next describes the disputed things found at Dumbuck. They were
analogous to those alleged to have been unearthed at Dunbuie. They were
"A number of strange objects like spear-heads or daggers, showing more
or less workmanship, and variously ornamented. One great spear-head
(figure 1), like an arrow-point, is 11 inches long and 4.75 inches
wide at the barbs. The stem is perforated with two holes, in one of
which there was a portion of an oak pin. It has a flat body and
rounded edges, and is carefully finished by rubbing and grinding. One
surface is ornamented with three cup-marks from which lines radiate
like stars or suns, and the other has only small cups and a few
transverse lines. There are some shaped stones, sometimes perforated
for suspension, made of the same material; while another group of
similar objects is made of cannel coal. All these are highly
ornamented by a fantastic combination of circles, dots, lines, cup-and-
rings with or without gutters, and perforations. A small pebble
(plate XV. no. 10) shows, on one side, a boat with three men plying
their oars, and on the other an incised outline of a left hand having
a small cup-and-ring in the palm. The most sensational objects in the
collection are, however, four rude figures, cut out of shale (figs. 50-
53), representing portions of the human face and person. One,
evidently a female (figure 2), we are informed was found at the bottom
of the kitchen midden, a strange resting-place for a goddess; the
other three are grotesque efforts to represent a human face. There
are also several oyster-shells, ornamented like some of the shale
ornaments, and very similar to the oyster-shell ornaments of Dunbuie.
A splinter of a hard stone is inserted into the tine of a deer-horn as
a handle (plate xiii. no. 5); and another small blunt implement (no.
1) has a bone handle. A few larger stones with cup-marks and some
portions of partially worked pieces of shale complete the art gallery
of Dumbuck."
It seemed as if some curse were on Mr. Donnelly! Whether he discovered
an unique old site of human existence in the water or on the land, some
viewless fiend kept sowing the soil with _bizarre_ objects unfamiliar to
Dr. Munro, and by him deemed incongruous with the normal and known
features of human life on such sites.