Note on the method adopted for setting leaning stones upright. By C. R. Peers, M.A., Secretary

The problem to be faced in securing the leaning stone numbered 7 on the plan was as follows. The stones of the outer circle, as first set up, were retained, approximately, in their relative places by the ring of lintels which they carried ; but when this ring was broken the pressure of soil round the feet of the stones was the only obstacle to deflexion, whether inward, outward, or sideways. When it is remembered that the average depth of the feet of the stones below ground surface is only 4 ft. 6 in., while the height above ground is 1 5 ft., and when the tapering shape of the feet is also taken into account, it will be seen that the probability of some movement is great. In judging, therefore, of the original position of a stone, its present position can give no absolute guide, and an adjustment which brings the centre of gravity as nearly as possible to the line of the vertical axis, and at the same time satisfies the fitting of the mortises on the lintels to the tenons on the uprights, where these exist, must be considered the best that can be obtained. Such an adjustment can of course only be made on a system by which the smallest movements of the stone can be controlled, and the method now to be described was devised with that intention.

A timber firaming of 8 in. by 8 in. pitch-pine baulks, vertical and horizontal, was placed round the stone, the horizontal timbers clasping the vertical timbers, and held together by long 1 in. steel bolts. For fitting to the irregular faces of the stone small pieces of wood, secured by folding wedges, were used, and felt was packed between the stone and the timber to prevent injury to the surface of the stone.

To the lower part of this framing were secured two steel joists, 1 4 in. by 6 in. by 20 ft. long, one on either side, and placed as nearly as possible at right angles to the axis of the stone. From the ends of the joists raking timbers, fixed to angle cleats, ran at an angle of about 45° to the top of the framing, in order to act as struts, and to convey the movement of the joists to the tops of the stones.

Under the ends of the joists were set travelling screw-jacks of 10-tons capacity, bedded on steel plates laid on the solid chalk. By raising or lowering any or all of these four jacks the angle of the upright stone could be altered in any direction, making minute adjustment possible, but for extra security, in case of any unforeseen slip, wire ropes were attached to the top of the framing to act as guys in different directions, and other ropes, secured to the lower timbers of the framing, were passed under the foot of the stone. The straightening operation began by raising the joist ends ½ in. on the side toward which the stone leaned, and lowering ½ in. on the other side ; this was continued in 1 in. movements till the stone. was upright, careful inspections being made between each movement to see that lashings, packings, etc., were not displaced.

The total southward movement at the head of the stone was 2 ft. 6 in., which was accomplished by raising the jacks at the north ends of the joists 14¼ in. and 14¾ in., and lowering those at the south ends 14½ in. and 10¾ in. respectively.

No movement or inclination to slip was observed during the raising of the stone.

Discussion

Dr. H. H. Thomas, Petrographer to H.M. Geological Survey, said that he was well acquainted with small specimens and sections of the Stonehenge foreign stones, and, through the kindness of Colonel Hawley and Mr. Tapp, he had now had ample opportunity of studying the stones themselves. He had not altogether been unprepared to find that, with a few exceptions, all the 'bluestones' were linked together by a common character, that made it practically certain that they had all been derived from the same area, and possibly from the same rockmass. The bluestones are mainly diabases that are remarkable for the presence of white or pinkish irregularly bounded felspathic spots that vary from the diameter of a pea to twice or three times that dimension. The speaker pointed out that the occurrence of such felspathic spots was highly characteristic of, and as far as he was aware confined to, the diabase sills of the Prescelly Mountains of Pembrokeshire. Many such general localities as Devon, Cornwall, Wales, and Cumberland had been suggested by previous writers as producing similar rocks, but now he was glad to be able for the first time to point to a locality where there existed a rock absolutely identical with that of which the majority of the bluestones was composed ; and it occurred both in situ and as boulders comparable in size to the Stonehenge monoliths.

Another highly characteristic rock of which there were two stones at Stonehenge, and of which an abundance of chips had been unearthed in recent excavations, was a beautifully banded spherulitic rhyolite. There should be no difficulty in identifying its source, and the speaker hoped shortly to be able to do so.

With regard to the majority of the bluestones, he felt certain that their ultimate source lay in the Prescelly Mountains and in the boulder- strewn area to the immediate south-east. All possible proximate sources, however, must of course be investigated, but he felt that the idea of Pembrokeshire boulders being carefully selected from practically all other rocks, and stranded on the high ground of Salisbury Plain by glacial action, was contrary to all sound geological reasoning ; and that such an assemblage of stones, of which so many were of the same type, pointed to human selection and conveyance from a distance.

He wished to point out that foreign boulders of large dimensions were not of infrequent occurrence in the low coastal region between Selsey Bill and the Isle of Purbeck, but, as far as they had been exiamined by the speaker, they had all proved to belong to types unrepresented among the stones of Stonehenge. He intended, however, further to investigate these boulders left presumably by floating ice, with the object of determining whether any were like those erected at Stonehenge. If it should be proved ultimately that Stonehenge types were represented," then the south coastal region would constitute a possible proximate source, but failing that there seemed to him no alternative but to go to the ultimate Pembrokeshire source for the material in question.

His investigations were as yet only in their initial stages, and he expressed the hope that he might be able to throw still more light on the sources of the foreign stones that had always been the subject of so much speculation.

Mr. Dale quoted Professor Judd's opinion of 1901 that the bluestones were glacial boulders left on Salisbury Plain ; and on one of the fragments exhibited he detected striae. Much had been collected for byilding purposes, and human transport from Wales would be a difficult matter.

Rev. G. H. Engleheart said the expert opinions left the meeting in a dilemma. The bluestones were declared not to be glacial, and even if they had been brought from Wales, it was difficult to believe that they were dressed only on arrival at Stonehenge. Transport of such an unnecessary weight argued lack of intelligence. In any case they were boulders and not quarried stones: one piece was striated, and he thought they were all of glacial origin.

Sir Arthur Evans congratulated Colonel Hawley and the Inspector of Ancient Monuments on the first season's work. The discovery of the holes indicated on Aubrey's plan was a distinct advance ; and he was ready to believe that a circle of small stones once existed inside the earth ring and had been subsequently removed, perhaps to the centre of the monument. The cremations would by general consent be placed in the later Bronze Age, and he was confirmed in the belief that the later history of Stonehenge was connected with the cult of the dead, its earlier elements being late neolithic. Recent discoveries tended to show that construction and reconstruction continued over a long period, and perhaps extended into the age of metal. Professor Petrie's metrological studies had shown that the outer circle was carefully drawn but did not have the same centre as the bluestones ; and three periods of construction had been deduced.

Professor Flinders Petrie (age 67) argued that the difference of centres indicated laying out at different times; and transport from Wales would imply unified government or tribal warfare. The latter seemed more probable, and the stones were perhaps a form of war indemnity. He hoped that special measures would be taken to secure everything found in excavating the Aubrey holes.

Mr. Reginald Smith drew attention to the absence of cinerary urns, and argued that the cremated bones must have been deposited in the Aubrey holes immediately after the stones were taken out; otherwise the sides would have crumbled and the cavities been silted up. Cremation was characteristic of the later Bronze Age, though not unknown in Yorkshire long barrows ; and there was nothing to date the deposits, which might represent human sacrifices on some solemn occasion. The patinated flints looked earlier than the monument, and differed from the pounders used for dressing the megaliths. In a few inches of soil, which had been disturbed more than once, finds of all periods might be expected, but it was curious that Roman pottery was common at various levels. The work had, however, only just begun, and it was inadvisable to draw conclusions from such scanty evidence.

The President felt that the discussion would bear fruit in the next report, and took much interest in the novelties already discovered, though any deductions from them would be premature. How the bluestones reached the site was likely to remain an unsolved problem, but thanks were due to Mr. Tapp for securing an official account of their nature and origin. Dr. Thomas's report was an important addition to the controversy. Colonel Hawley seemed to forget his years at Stonehenge ; and in thanking him for his report the Society would wish him and his colleagues all success in the coming season.