This structure was in some respects the most important of the entire series. As the photograph (Plate XII, fig. 4) shows, it is of large size, and beautifully regular. It is indicated only by an indefinite symbol, not as an ancient monument, on the Ordnance map, though it is perhaps the most conspicuous of the whole series. It is 87 feet in diameter, and about 25 feet in height. The structure is built of stones rather smaller than are the other carns. The top is slightly hollowed, possibly as a result of the collapse of the chamber. A plan and section of the carn will be seen in Plate XIX.
The entrance, as in the others, is toward the north. It is of a much more monumental character than the small creep-holes which give admission to the other carns, being 4 feet 7 inches high, and lined by massive jamb-stones supporting lintels, one of which is 7 feet in length. Plate XIII, fig. 1, shows this doorway.
Looking south through the ruined doorway of Cairn F into the collapsed chamber in 1911.
The chamber into which this doorway gives admittance is quite different in plan from any of the chambers in the other carns. It is in the form of a passage, 12 feet long and at the entrance 2 feet broad, but widening inwards, in a square recess, marked off by a sill-stone, 7 inches high, and having two similar recesses, with splayed sides, on either hand.
The plan of the chamber was marked all round by massive slabs of lime stone, roughly brought to a square shape, and set on edge. These slabs were carefully selected, being all from one quarry-bed. Above these were laid either long stones or horizontal slabs. In the upper courses large slabs only were used, which gradually oversailed till they approximated close enough to bear cover-slabs roofing the whole chamber.
These oversailing slabs were not horizontal. Packing of small stones was inserted over each, the face of the packing being flush with the edge of the slab below. This packing acted as a wedge tilting the slab backwards, so that rain-water that percolated between the small stones of the carn was shed off by the slabs and prevented from penetrating into the chamber. See the Plan and Sections, Plate XVIII.
Eight water-rolled limestone pebbles from the chamber of Cairn F. The stones were buried beside the limestone pillar or standing stone within the chamber.
The labour of erecting this chamber must have been enormous. The much simpler work of excavating it and removing the broken stones that had fallen into it was no light task; the manipulation of the gigantic slabs of which the building was formed could not have been carried out at all except by a community much more highly organized than we might have expected to find in the middle of the Bronze Age.
The constructional skill displayed is beyond all praise. The use of squinch-stones (slabs running diagonally in the corners), by which the length of the space to be spanned is reduced, is specially noteworthy.
The view to the west from Cairn F. The triangular profile of Croagh Patrick can clearly be seen 75 kilometers distant.
Smashing Capstones
Similar squinches occur in the roof of Brugh na Boinne, but on a smaller scale. The top-stone of the chamber was a great massive slab, 9 feet by 6 feet 6 inches by 1 foot thick weighing, roughly speaking, about four tons. This stone is seen in Plate XIII, fig. 1, marked by a walking-stick lying upon it. The doorway of the carn is there shown in the foreground. In order to get this stone out of the way, we had no alternative but to break it up. To have attempted to move it would have been a dangerous and expensive undertaking, and probably the doorway underneath would have suffered serious injury.
The architect who carried out the work of constructing this chamber had made one unfortunate miscalculation. A huge slab, 9 feet 3 inches in length, which he had inserted close to the inner end of the western side, had not been equal to supporting the cross-strain put upon it. It had split into two, and, in falling, brought down all the upper part of the roof. An avalanche of small stones from the outer shell of the carn had rushed into and filled up the chamber: on the top of these the capstone above described lay misplaced, in the position in which it is shown in the photograph. This was taken after we carefully had cleared out the small stones from the chamber, as much as we could with out disturbing the large slab. The accident is most deplorable, as it ruined what it is no exaggeration to call one of the most impressive and interesting ancient structures remaining in Ireland.
The plan and sections on Plate XVIII show without need of further description the design of the structure and the relative sizes of its parts. It will be seen that it can also be fairly described as consisting of two chambers separated by a narrow doorway, with two grave-recesses in the outer and three in the inner. The interments had not been confined to the grave-recesses: bone dust, much trampled, was found in places on the floor. The sill of the grave-recess on the left-hand side, within the entrance, was missing: it is restored in dotted lines on the plan. We suspect that by an oversight it was removed by ourselves in clearing out the debris of large and small stones that filled the chamber.
Sections and dimensions of Cairn F from 1911.
The perspective view on Plate XIX is designed to illustrate more clearly the elaborate and ingenious construction of this carn. But to prepare a satisfactory view was found extremely difficult. The narrow doorway in the middle of the chamber makes it next to impossible to find a point of view from which enough of the construction can be seen in one coup d’oeil to be at all informing. Plate XIII, figs. 2-4, shows portions of the building that display the masonry.
Fig. 2 is the north-west corner of the western grave-recess in the outer chamber; fig. 3 is the south-east corner of the eastern grave-recess in the inner chamber; fig. 4 shows the central grave-recess, and also the most interesting and detail of this monument, which it is now time to describe.
The main panel of art within is lit up with a beam of light, which penetrates the chamber not long after sunrise in early November and Feburary. Cairn L, Loughcrew November 1997.
The Pillar Stone
This is a standing stone, 5 feet high, with a fairly uniform thickness of 7 1/2 inches east to west, and 9 inches north to south. It cannot have served any constructional purpose: not only is it too slender, but it seems never to have stood quite upright, so could not have borne any other stone or stones. The roof of the chamber vertically over this stone must have been well-nigh 16 feet above the ground, or 11 feet above the top of the pillar.
The standing stone within Cairn F, photographed by R. A. S. Macalister in 1911.
The stone had been snapped across 15 inches above the ground; in falling, it cracked the sill-stone of the central recess behind it, across which it was found lying. The fractured surfaces, however, are both intact and fit exactly. The broken part, however, will not stand on its base without support: a little Portland cement, and probably a metal clamp, would be necessary if haply this in teresting building be ever restored, as one likes to hope may some time be the case.
The accident, whatever it was, which broke the stone, was not the same as the catastrophe that brought the roof down. For after the stone had fallen, the ashes of a burnt human body were laid on the butt end of the prostrate part. It is possible that the resting-place was chosen on account of some special sanctity attaching to the stone; for after much discussion we can find no satisfactory alternative to regarding it as a religious emblem. This being assumed, the question presents itself whether we may not have here something more than a mere burial place. May we not have some sort of temple? The grandiose scale of the architecture, the large entrance doorway, the peculiar ground-plan, and, above all, the standing stone, all mark this carn out conspicuously from the rest.
The Whispering Stone, a limestone pillar within Cairn L at Loughcrew, is the only other known example of a standing stone within a neolithic chamber in Ireland.
At the foot of the stone, on the eastern side, is lying another, 1 foot broad, 9 inches thick, and 3 feet long. Bone debris in plenty lay under it. A third stone, 2 feet 6 inches long, 6 inches thick, 9 inches broad at one end and 5 inches broad at the other, lies at the northern end of the south-western grave-recess. The position of both these stones is marked in the plan. There is no evidence that they ever stood upright, but that they had been placed with intention where they were found seems undeniable.
The last point to notice about this important carn is the use of the erratic blocks of silicified sandstone which are frequent in the neighbourhood. Those used in the buildings are shaped rather like cheeses, with convex sides and flattened top and bottom.
One such will be seen in the photograph, fig. 3 on Plate XIII, the inner stone of the topmost course in the corner opposite that in which the man is leaning. Here it is merely used as an ordinary building stone: but in another place the sandstone is used probably because it was found by experiment that it was capable of bearing a heavier crushing strain than was the limestone. This was on the jambs of the central doorway: on the top of each was a sandstone block; indeed, on the eastern jamb there were two, one on the other like the drums of a column.
Evidently at these two points, in the middle of the two long sides, the weight of the massive roof was expected to be concentrated; and it increases our respect for the mind that planned this fine building when we see that he had the discrimination to choose an especially hard stone for just this part of the structure. The same foresight is displayed by the builder of the first of the two dolmen like structures, described below.
(1) The oversailing lintels seen in the sections on Plate XVIIT above the lintel shown in this photograph were in situ when the excavation began, and appear in Plate XIV, fig. 1. After measuring, we were obliged to remove them, as the top lintel (supported by a wooden prop in the photograph) was loose, and the second was cracked longitudinally, and neither could have stood without the support of the small stones which had filled the chamber completely, and which, of course, we had to clear out. The great slab whose failure caused the collapse of the building is seen on the right hand side of this photograph, under the foot of the wooden prop).
