Rock Art Recording Techniques

Rock Art and Red Socks

(Mizen Magic 26: Balteen)

What do red socks have to do with rock art?  Well, nothing really, but they turned out to be surprisingly useful this week.

It’s been ages since we talked about rock art, hasn’t it? Thinking about that, I decided to do some tidying up in our blog and I have created a special page for Rock Art, and another one for Mizen Magic, since this post also fits into the Mizen Magic series. 

Robert and I set off to hunt down rock art we haven’t yet seen on the Mizen. The National Monuments site contains two records for Cupmarked Stones in the townland of Balteen, and both proved easy to find. (If you can’t remember what a Cupmarked Stone is, take a look at this post before reading on.) The first is along the road that leads from Barley Cove to the North Side. That’s my butt marking the location of the rock, above.

It’s built into the bank and we might not have been as quick to spot it as we were unless somebody else had already found it and cleared away some of the overgrowth – I suspect Rock Art Kerry, AKA Aoibheann Lambe had been there before us, perhaps a couple of years ago. We usually remember to bring a soft brush with us for a gentle cleaning of the rock surface (lots of moss on this one) but we had forgotten this time. The red socks came to the rescue.

This is a lovely example of a cupmarked stone – although it’s possible there is more on it than cupmarks only. The central cupmark appears to have some carving around it that helps to mark it out and elevate it – not a complete circle but an arc that may end in an expanded finial. We have sent the photos off to UCC for a 3D rendering and this may clarify this aspect of the carving. Here’s a short video – see what you think about that arc.

Meanwhile, since it’s hard to make out what’s in the surface of a grey rock on a grey day, clever Robert has made a scaled drawing of it. We know that cupmarked stones like this can date anywhere from the Neolithic (about 5,000 years ago) up to the Bronze Age (ended about 2,500 years ago), and that the cupmarks were probably made by picking or bashing them out with a stone cobble, but we don’t know why they were done, or what meaning the cupmark itself may carry.

We also don’t know if this one is in its original position, but it’s likely that it is not. It is currently incorporated into the bank at the side of the road, leading us to suspect that it was found in the vicinity and built into the wall to give it a place where it would be visible to all passers-by.

The second one (above) was a surprise! First of all, it’s enormous! It looks like it may have been a capstone for a large structure, or perhaps a boulder burial. However, it’s difficult to determine if there is anything underneath and it may well be a glacial erratic that simply ended up here. This one is in the same townland but it’s on private property, so we are not pinpointing it on a map, at the request of the owners – but they are happy to give permission to see the stone and they welcomed us to take photos and tell them a little about rock art in general. There are nine cupmarks, from large to small and some appear to be arranged in a rough semi-circle – something we have observed on other cupmarked stones.

I am trying something a little new with this post – doing short videos to see if this helps to convey more than a photograph might. I’d be interested in your feedback on this. Note: You may have to play the videos on YouTube – sorry if this aspect isn’t working right for everyone!

Just when you think you have seen all the Mizen has to offer, it reveals yet more of its secrets!

New Rock Art Find in West Cork

“I’ve found a funny rock carving and a friend told me to ring you” – that’s my favourite type of call to get! It doesn’t always work out: sometimes the marks are machine-made, or a natural geological feature of the rock. But the anticipation is always there that this time it will be the real thing.

And it was! Our caller was John Minihane, a retired harbour master and a Harley enthusiast, living in a beautiful traditional farmhouse near Union Hall, once the home of his grandmother. He had been tidying up the back garden and pulled ivy off what seemed to be just a big rock in a bank separating his property from a neighbours. It turned out to be a standing stone with prehistoric rock art on it.

Not all rock art is spectacular – some of it can be underwhelming, consisting of only a few cupmarks. Take a look at some of our previous posts on rock art (C2 on our Navigation Page) to see some of the examples, from simple to complex, we have written about. The one (below) is possibly one of the most iconic pieces of rock art in Ireland – it’s from Derrynablaha in Kerry.

This photograph (above) shows the rock art panel in its location, high in the Kerry Mountains, overlooking a beautiful valley and lake. The image is by Ken Williams, used with his permission. Ken is Ireland premier photographer of archaeological subjects – read more about him here or better yet visit his amazing website.

The latest thinking about Atlantic Rock Art (it occurs all down the Atlantic Coast, from Portugal to Scotland) is that it is Neolithic – that is, about 5,000 years old. In its elemental, form, the humble cupmark, it persists into the Bronze Age, sometimes occurring on Wedge Tombs and Boulder Burials. So this standing stone, with cupmarks and grooves, might be anywhere from 5,000 to 2,500 years old.

Most rock art is found on bedrock (like Derreennaclogh, above) or earth-fast boulders, but in West Cork, we do have other examples of rock art on standing stones. Two can be found about 9km east near Rosscarbery, both in the townland of Burgatia and both with cupmarks and cup-and-ring marks. Another is located on the townland boundary between Knockanoulty and Barnabah, about 14km to the SW. I’ve shown that one below, both as a photograph and as a drawing.

When I was a student (back in the dawn of time) and recording rock art, the conventional method was to chalk in the carvings, trace it all on to clear film, re-trace it in paper using Indian ink, and then have that photographically reduced. That’s how I produced the drawings above. Robert has used his architectural drafting skills to produce drawings more recently – below is his rendering of the cupmarked stone a local farmer showed us quite near where we live.

Mostly, nowadays, archaeologists favour techniques that do not interfere with the rock surface, and that usually means a photographic technique known as photogrammetry. The idea is to take lots of photos (150 in this case), moving at a steady rate and distance across the surface of the rock, load these into a program that can create a 3D image, and see what comes out.

We are very grateful to Nick Hogan of the University College Cork  Department of Archaeology who used their sophisticated software to create the 3D image. It’s been fun to play with the files he sent us, which are the best way of seeing what’s actually on the rock surface. 

You can set up a grid, or rotating axes, and turn the model so that the light hits it in different ways. This can help you to discern small cupmarks that don’t show up well in photographs. In the case of this rock, the thing that was hard to make out was the exact shape of the groove, and the 3D model shows this up well. If you turn it sideways it looks like an owl – but this is purely a chance occurrence – this art was strictly non-representational (although there’s a chance we might find a  deer or an axe some day, but that’s another story).

It’s always exciting to find a genuine piece of undiscovered archaeology! Thank you, John Minihane, for inviting us over to see your find and allowing us to record it. And thank you, Nick Hogan for the 3D modelling. A most satisfying project all round.

Nine beans rows will I have there, and a piece of prehistoric rock art!

Revealing Rock Art: 150 Years of Images

This week a powerful image from Ken Williams of Shadows and Stone (copyrighted, used with permission) lit up the Irish Rock Art Facebook Page (180,000 people had seen it at last count, and it’s been shared more than 1500 times). The photograph, taken with Ken’s signature blend of natural and artificial light, was of a stone in Kerry often known as the Staigue Bridge Rock Art, although technically it’s in the townland of Liss.

As it turns out, this is one of the best-documented rock art panels in Ireland, with images dating from the middle of the nineteenth century to the present day.

Taken on a recent visit to Liss/Staigue Bridge Rock Art site. This is probably what a casual visitor will see. Can you make out any carvings?

The response to this photograph highlights several important features of Irish rock art. First of all, it seems people are hungry to know more about these enigmatic carvings, and yet rock art is one of the least known aspects of Irish archaeology. Time after time, as Robert and I present exhibitions or give talks, we meet up with a near-universal response of “How come we’ve never heard about this before?”

Another view of the top section of the panel

Secondly, a photograph like this is not normally what you observe in the field. Commonly, rock art (and this one is no exception) is actually difficult to see under most lighting conditions. This rock is just off a popular hiking trail and the vast majority of walkers are unaware of what is a few meters from their path. Even if the route went right alongside it, most walkers would pass by without noticing anything unusual.

This will give you an idea of the extent of the panel

Thirdly, it is no longer possible to record rock art by any of the traditional methods that were in common use up to the 1990s. Nowadays, recording techniques that do not impact in any way with the rock surface are preferred, and that limits us to what can be imaged through photographic and scanning technology.

Aoibheann Lambe’s virtuoso photograph – this is the panel in the second photograph, taken from almost the same angle but under perfect natural lighting conditions. © Aoibheann Lambe

There are currently three ways in common use to photograph rock art so that the carvings will show up. The first is to use the natural low, slanting, shadow-casting, light at sunrise or sunset. Rock Art Kerry, the work of archaeologist Aoibheann Lambe, has an outstanding photograph of the rock surface using only natural light. Given our climate, it is likely that many visits to the rock in all kinds of temperatures, early in the morning or late in the evening, were necessary before the perfect shot was possible. Aoibheann’s Facebook page is the place to be these days for new finds – she is making discoveries at a breathtaking pace!

Another of Aoibheann’s photographs – this one shows the extent of lichen growth on the rock surface, which often functions to obscure carvings. © Aoibheann Lambe

The second is to use flash photography – a technique that Ken Williams has perfected and uses to great effect to show up even faint carvings. We’ve seen Ken working – this isn’t a mater of a simple flash on a camera – multiple flashes are deployed with a skill that comes from long experience, and respond to an electronic trigger on his camera.  If you haven’t already done so, a visit to his site is an absolute must for anyone interested in rock art – or indeed in Irish archaeology.

Finola and Robert from Roaringwater Journal and Ken Williams of Shadows and Stone at Derrynablaha in Kerry

The third technique is that of photogrammetry. In essence, this is the combination of multiple high resolution photographs to construct a 3D image of a rock surface. The Discovery Programme has been sponsoring 3D imaging of various national monuments, including Ogham Stones and Sheela-Na-Gigs, for some time. Under this program, The Dingle Museum (Músaem Chorca Dhuibhne) has produced a series of 3D images, including an excellent one of the Liss/Staigue Bridge rock art panel.

The top panel rendered in 3D – this is a screen capture. © Corca Dhuibhne 3D 2017

It is particularly exciting because it’s unusually clear (rock art 3D images can suffer from lack of clarity for a variety of reason) and also because this technique allows an image of the whole panel, whereas photography can only capture pieces at a time.

These stills have been captured from the 3D images on the Museum site but they do NOT compare with the experience of viewing and manipulating the 3D images on screen. It’s brilliant work, so please go to their page for the real thing. © Corca Dhuibhne 3D 2017

But back to the past, when it was still possible to produce drawings of the carvings. Back, in fact, to the 1850s! There were two Irish antiquarians called the Rev Graves. The better-known one was the Rev James Graves of Kilkenny, but the one we are concerned with here was the Rev Charles Graves, Bishop of Limerick and a noted mathematician, scholar, antiquarian, and President of the Royal Irish Academy. He was fascinated by Ogham and on a trip to view Ogham stones in Kerry he came across other ‘inscribed rocks’ of a type he was unfamiliar with. He wrote up his findings and presented them to the Academy in 1860.

Taken from the Wikipedia article on Charles Graves. Image above by Anonymous – Church Bells (1874–1875)) W. Wells Gardner, Publisher, London, Public Domain

The good Bishop had none of our modern scruples about interfering with the rock surface, or removing the turf to see what else he could fine. He did both: three feet of turf was stripped back to reveal the extent of the carvings and a rubbing was made from the whole surface, which was later converted to a survey-drawing. This, to this day, is the only drawing we have of the complete carving.

When I wrote my thesis on The Rock Art of Cork and Kerry in 1973 I said this about Charles Graves:

The first paper devoted to rock art in Ireland was by Rev. Charles Graves. In 1860 he read a paper to the Royal Irish Academy entitled “On a previously undescribed Class of Monuments”. His paper, mainly concerned with Co. Kerry, is still very valuable and his drawings and observations are often more accurate and more reliable than many later accounts.

My own drawing was done in 1972. The technique I used then was to chalk in the carvings and trace them onto clear plastic film. That tracing was then re-traced on to good quality paper using indian ink and a stipple technique and then photographically reduced by a professional printing firm. It is naturally an imperfect and subjective method, but long practice enabled me to produce surprisingly accurate renditions which stand up well to modern recording techniques.

I confined my drawing to the main area of carving and used Graves’ drawing as an additional illustration

There are few examples of Irish rock art with the pedigree of Staigue Bridge. It is classic cup-and-ring art in its execution but also contains the unusual elements of very large circles surrounding small cupmarks. It is enormous – a fact that would never have been appreciated if Graves had not determined to find the true extent of the carved surface (although of course we do NOT condone this practice now). It has a literature that goes back a century and a half, and was one of the first pieces of Irish rock art to be described and illustrated. It’s a national treasure.