Issue 162
Newsletter – Issue 162, March 2007
Society Activities
Lectures
The April lecture (Wednesday, 18th) is Dr Jill Turnbull on Glassmaking in Edinburgh and the Lothians while on Tuesday, 15th May we have member Ian Paterson on The Demise of Knossos – a stratigraphical problem.
Outings
1)Outing to Lamb’s House
Our next outing is to Lamb’s House in Leith. It is at the corner of Shore and Bernard Street, the latter being a continuation of Commercial Street (check your Edinburgh Street map if in doubt). We will meet there at 3.30pm on Wednesday, 25th April.
Lamb’s House is a large, impressive 16th century building whose earliest known owner was a merchant named Andrew Lamb. The most important event linked to the house is that Mary, Queen of Scots, had a wee rest there after her journey from France in 1561. It is not recorded whether Mrs Lamb asked her whether she had had her tea.
It was reconstructed in the 17th century and is very attractive with steeply pitched roofs, crowstepped gables, white harling and a corbelled stair tower. As usual for this period the design shows strong Dutch influence. This is also reflected in the interior layout where the family lived downstairs and the merchandise was stored on the first floor.
In recent years it was used as an Old People’s Day Centre but it is now occupied by Friends of the Earth who have kindly offered to show us round – in view of this a good turnout would be appreciated.
2)Trinity House
10 members of the Society paid a visit to Trinity House, Leith on 20th March. It was set up in the 14th century as an incorporation of ship owners and master mariners as a charity for impoverished or disabled seamen and an important part of the service was a hospice. The original building (site unknown) was destroyed during the ‘rough wooing’ in 1544. A new building was constructed on the present site shortly after but all that remains of it are vaulted cellars under the present building which was built in 1816 with an interesting classical facade. An attractive feature inside is an intricate plaster ceiling in the dining room. The walls are covered by oil paintings of mariners and ships but the one that stands out is that of Admiral Duncan, victor of the Battle of Camperdown. There are also fine ship models, covering a long period from sail to steam, examples of equipment used in navigation such as telescopes and sextants and many other sailing memorabilia. This was a very well spent afternoon and our thanks go to the enthusiastic, pleasant and well-informed guide. So enthusiastic that she may join us for the visit to Lamb’s House.
Castlehill, Penicuik
The dig has recommenced and will continue through the summer. Sir Robert Clerk has given permission for a further geophysical survey to be made in the field to the south of Castlehill for us to see whether we can find any anomalies that align with crop marks that appear on two separate RAF photographic surveys. We appear to have found a working site on the hill but no domestic debris – was the residential area on this sheltered south side?
Magnetometry at Lauriston
The initial work in the Farl O’Cakes field, which is reputed to be the site of the burial ground for the Roman fort at Cramond, was a ground resistance survey. It was written up as one of our Geophysics Papers in March 2006. The highs and lows in the printout were difficult to interpret and one of the conclusions was that a magnetometry survey over the same area should be conducted. An offer to perform the survey by a geophysicist, who owns a Bartington Fluxgate Gradiometer, was too good to miss. On 8th March we set out the corner flags of the 24 20 by 20 metre squares and Peter set up his equipment and took all the readings. We took five day sessions while the magnetometry survey took about 2½ hours!
Large areas of Scotland are well known for presenting very ‘noisy’ magnetic pictures due to a lot of glaciated igneous boulders incorporated in the soil – these boulders all give significant positive magnetic responses. The Farl O’Cakes field appears to be a good example of this phenomenon. We now have the task of attempting to interpret the magnetometry in conjunction with the ground resistance printout to see where we have coincident responses and whether they form any pattern. The initial comment from Peter is that some of the magnetic responses to the east of the field could represent rig and furrow from earlier cultivation.
Issue 161
Newsletter – Issue 161, January 2007
Society Activities
Committee
For those of you who were not at the AGM, Dave Jones, after many valuable years on the Committee including a spell as Chairman, has decided to stand down. I am sure you will all join us in thanking Dave for his sedulous work on the Committee and in hoping that we will still see him at all of our digs, ground resistance surveys and other Society activities. Jill Strobridge was voted onto the Committee at the AGM.
Lectures
Having been to Iran in January we come down to earth (!) in February with Dr Stephen Carter on A Soil Scientist’s Guide to Archaeological Sites – Wednesday, 14th Feb at 7.30pm at 23a Fettes Row.
The March lecture is by Andrew Broom – The Appin Murder 1752 – Tuesday, 13th March.
Outings
The National Museums of Scotland Conservation Unit
On a cold bright day, the 31st October, about 12 members of the Society were shown round the Conservation Unit at Granton. 0ur host was Dr Theo Skinner, Conservator of Marine and Wetland Archaeology.
The undoubted star of the show was the Tay log boat. Most of us had seen dugout boats before, but were still impressed by the sheer size of this one. It was 9.25 metres long, about 1.5 metres wide and must have been more than a metre deep. It weighed about 2.4 tonnes. Part of the bow had been eroded, but the stern was in good condition with a stern post that slotted into a deep groove. The stern post had been removed, and was lying in its own tank of water. The main hull was under polythene, being continuously sprayed with fresh water. The cover was removed so we could see every detail of its blackened 3000 year old surface. It was, Dr Skinner told us, not hollowed out by fire but carved out with an axe or adze. The oak of which it was made would not burn easily enough for fire to be effective. I peered closely but could see no axe marks. I didn’t doubt Dr Skinner’s deductions, but was impressed by the skill of our Bronze Age predecessors.
As well as the groove for the stern there were 2 step‑like ridges, another shorter groove, and holes in each side of the hull just below its rim. None of these features had yet been explained. Along the bottom of the boat a long crack appeared to have been repaired by a black glutinous substance. No doubt future analysis will clarify its nature.
Trying to picture the boat in action, it was clear that any oarsmen would probably have had to stand up. It was an impressive object. They must have had very large oak trees and fine craftsmen 3000 years ago.
After spraying with fresh water to remove the salt, it will be sprayed with or soaked in polyethylene glycol. When 30 per cent of the water has been replaced, the boat can be freeze‑dried before going on permanent display. To do this to the complete boat would cost £150,000, but the budget is only £25,000. The solution, unbelievably, is to cut the boat into three and process it piecemeal.
We were shown many items of interest: some from a ship called the Swan that sank in the Sound of Mull in the 1650s, others from a ship called the Dartmouth. A small ceremonial brass cannon had a cast iron carriage ornamented with a lion holding the globe. Three of the four carriage wheels were found, and a replica made to replace the 4th. Cast iron contains a lot of carbon and sea water gradually corrodes and leaches out the iron. The surprising result of this was that the original wheel, now largely composed of graphite, was many times lighter than the replica.
In another vivid demonstration, Dr Skinner showed us a computer animation of how waterlogged wood shrank as it dried ‑ unless it was properly conserved.
A large tank contained pieces of timber from the hull of the Dartmouth. These had been under water since 1974. Originally Dr Skinner’s predecessor had hoped to conserve them by a new process that involved the alarming prospect of heating them in a bath of acetone. Fortunately this plan has been abandoned.
We were shown small slivers of wood and challenged to identify them. They were Roman writing tablets from Newstead similar to those from Vindolanda but without the writing!
Three, it has to be said, rather undistinguished pieces of wood we were told came from our own Fast Castle excavations and would soon be returned to us.
To demonstrate how the distortion of wood made it difficult to reconstruct objects our host then showed us a wooden mould he had made with conserved strips of wood tied around it. It was, he told us, a small barrel. Neatly side‑stepping the question of why anyone would go to the bother of making such a pint‑sized barrel, he informed us that this reconstruction had taken him the best part of a month.
I was impressed by the patience and dedication of Dr Skinner and his colleagues ‑ it is not a job that everyone could do. We, who marvel at the exhibits in museums, owe a lot to them, and it was a great privilege to be able to see behind the scenes. Thanks to Bill for arranging the visit, and to Dr Skinner who, in his quiet way, imparted a lot of interesting information in a short time.
Finally, I can’t resist pointing out that Dr Skinner is not just a ‘back‑room boy’. On his computer was a beautiful seascape of a channel between wooded headlands. I asked him if this was the Sound of Mull where the Swan had sunk. ‘No’, he said, ‘that’s the view from the back of my boat.’