By Dr Nora White, OG(H)AM’s Irish Postdoctoral Researcher
In 2013-2014, as part of the Ogham in 3D project, a preliminary survey of the carving techniques used for monumental ogham inscriptions in Ireland was carried out in collaboration with a professional sculptor and letter-carver, Séighean Ó Draoi. This blog post presents the findings of an unpublished initial report. This preliminary work will form the basis of more extensive investigations into the carving techniques, materiality and palaeography of early Irish epigraphy (both ogham and Latin alphabet inscriptions) in the new EMISoS (Early Medieval Irish Scripts on Stone) project, based in the Department of Early Irish at Maynooth University and funded by the Taighde Éireann – Research Ireland Pathway Programme.
Outline of the aims and methodology
For the purpose of this survey, a selection of ogham stones in the National Museum of Ireland (NMI) collection, from various locations around the country, were examined in close detail. All of these examples are from the classical period of ogham (5th-7th century A.D., see Periods of Ogham Usage blog post) and the inscriptions are invariably carved vertically on the stones, using the edge or arris as a stem-line. The aim of the survey was to try to determine for each inscription:
- any evidence for preparation of the stone prior to carving (including removal of earlier inscription)
- the carving technique(s) used
- the tool(s) used
- the similarity, or otherwise, of the inscription with any additional features (generally crosses).
In addition to techniques and tools, another crucial element in the choice of carving technique is the geology of the stone. It was, however, beyond the scope of this modest study to include a scientific assessment of the geology of the ogham stones. Therefore, informal and approximate assessments of the geology were made in each case.
Following the initial examination phase, the next step was a practical experiment in which Séighean recreated as closely as possible the various techniques observed.
Overview and general observations
The following observations build on the work of Gifford Charles-Edwards who used practical experiments in letter carving (mainly Insular Latin letters but also ogham) as part of her unpublished PhD study (2006, University of Wales, Bangor). Ogham inscriptions are found on many different types of stone, mainly dependant on what was available locally. The inscriptions were generally executed using carving techniques and tools not unlike those still used today. As Nancy Edwards (2007, 36) found to be the case with Welsh oghams, ‘there is no evidence for any systematic preparation of the surface prior to carving. The style of cutting the ogams is variable and is likely to have depended upon the individual mason and the geology of the stone’. Although there is quite a range in the standard of design and layout, ogham inscriptions in general can be fairly described as being relatively crude. Edwards (2007, 43) pointed out that crude looking inscriptions are not unique to ogham as can be seen in the roman-letter inscriptions of south-west Wales: ‘There is no evidence that the roman-letter inscriptions, either horizontal or vertical, were laid out on ruled lines; in fact, unevenly laid-out text and irregular lengths of lines and spacing of letters are characteristic features, just as they had been of some earlier provincial Romano-British inscriptions (Tedeschi, 2001: 16)’. However, as Macalister (1949, 119) first noted, a small number of the ogham stones examined to date appear to have guide-lines (Macalister’s ‘minute pinscrapes’) in the vicinity the inscription, which may indicate some degree of layout planning on the part of the carver.
In his 1949 Corpus inscriptionum insularum Celticarum, Macalister frequently, though by no means always, gives a brief mention of the carving technique. Sometimes he simply states that an inscription is ‘inscribed’ or ‘incised’ but some of the more descriptive terms he uses include: ‘chiselled’ (suggesting a flat-chisel), ‘cut (not pocked)’, ‘pocked (and rubbed)’ and ‘in fine scores’. These terms, on the whole, appear to roughly coincide with what we have found so far in our analysis.
Tools
Although stone tools may have been used in some cases for carving ogham inscriptions (on softer stones), there is much evidence (in the form of tool marks) for metal tools being used, as is the case for stone carving generally in the early medieval period. The following are brief descriptions of the main tools for which we have evidence of use for ogham carving.
Point (also punch): The point chisel is a metal hand-held tool consisting of a shaft and a pyramidal point at one end. The length of the point varies depending on which material it is being used on. The point chisel is usually hit against the stone with a metal hammer, sometimes a wooden mallet, and is the basic chisel used for most carving. It is used primarily for roughing-out and basic shaping, though it can also be employed as a finishing tool to achieve a particular effect. The way in which the chisel is applied to the stone varies according to the effect desired and the material (Wootton 2013).
Flat chisel: The flat chisel, like the point chisel, is a metal hand-held tool which is usually struck with a metal hammer, or wooden mallet. It consists of a shaft and a flat, sharpened cutting edge perpendicular to the line of the shaft. The width of the cutting edge can vary significantly, between 5 and 100 mm; the wider varieties are sometimes called bolsters or droves. Further variation is found in the profile of the corners of this cutting edge. Sometimes they are rounded so that they do not catch on anything during delicate work, but often they are left squared and sharpened for the careful application of detail and especially for letter-carving. The flat chisel is typically used for applying detail, smoothing surfaces and finished forms. It is usually held at 35-60° to the surface of stone but like other chisels it can be used in various ways, carefully to smooth or more roughly to shape quickly. The traces left behind by the flat chisel tend to consist of almost smooth sets of parallel straight lines, sometimes barely noticeable when the carver has worked particularly carefully (Wooton 2013).
Carving techniques
Pocking: this technique is carried out using a point chisel struck with a hammer or mallet (percussion). Carving ogham with this technique results in a rough, usually quite broad stroke, often rubbed smooth (‘pocked and smoothed’). Occasionally, when a particularly sharp ‘conical’ point has been used, this tool can leave behind distinctive pin-holes in the groove that can only be seen with very close examination. This technique appears to have been influenced by metalworking (Charles-Edwards 2006).
V-section cutting (equivalent of Macalister’s ‘cut’/’chiselled’): this technique is usually carried out using a flat chisel struck at an angle with a metal hammer or wooden mallet (percussion). The technique produces cleaner, neater and usually narrower ogham strokes than pocking, with a distinctive V shape and a line visible at the bottom of the groove.
Scoring (equivalent of Macalister’s ‘minute/fine scores’): this technique may be carried out using any sharp object, such as the point of a point chisel or the corner of a flat chisel and forms thin lines by friction or cutting, usually with a flat-bladed chisel, rather than through percussion. These strokes often taper off at the ends and sometimes accidental double lines appear. Broken lines have also been observed across uneven surfaces. It could also be produced by tapping lightly on a flat chisel at a 90º angle to the stone. The result is a very fine stroke, which seems to be more common in ogham stones from the Cork area. However, examples do occur elsewhere in the country.
Case studies
I-KER-087: Whitefield 3, Co. Kerry (CIIC 217, 1 of 4 ogham stones found reused in souterrain)
Sandstone, ogham on two edges (up-up), incomplete (top broken off). Plain crosses on 3 faces.
Carving technique(s): Pocked in neat, evenly-spaced, average-length strokes, with pin-holes from a sharp point chisel still visible in the base of the consonant strokes. This is similar to the two other inscriptions from the same site. The vowel strokes are shorter but appear to have been executed in the same way. However, the execution of the crosses differs considerably from that of the ogham strokes, described by Macalister (1945, 211) as ‘incompetently formed, in contrast to the general neatness of the inscription, and evidently by different or later hands’. Two of the crosses have broad, shallow grooves (one is partially lost due to a break at the top of the stone) and the third is narrower and possibly rubbed with a hard stone.
I-COR-093: Bunkilla, Co. Cork (found during drainage works close to a church site)
Sandstone, long and narrow, ogham on 3 edges (palimpsest).
Carving technique(s): The earlier inscription (weathered or possibly defaced with a point chisel) appears to have been originally pocked on three edges. The later inscription is on the left edge and the consonants are deeply cut or scored, with some double lines evident, in long, narrow strokes tapering off at the end. The vowels appear to have been cut with a flat chisel but they are narrow and not as distinctively wedge-shaped as in other inscriptions.
I-COR-049: Ballyhank 4, Co. Cork (CIIC 100, 1 of 6 found reused in a souterrain)
Sandstone, ogham up on one edge.
Carving technique(s): Fine strokes v-cut or scored with a flat chisel. Consonant lengths vary according to the contours of the stone. Vowel strokes are shorter but executed using the same technique (not wedge-shaped). The B stroke, found some distance before the name, is different as it shows sign of being pocked rather than v-cut and is shallower. It is also straight where the other strokes on the B-surface are sloped. Ogham stones from this site show much variation in technique (Ballyhank 3 is pocked and 4 is ‘roughly scratched’).
I-WAT-030: Kilgrovan, Co. Waterford (1 of 7 discovered at an early ecclesiastical site)
Sandstone, inscription incomplete, up-top(-down?).
Carving technique(s): Vowels are v-cut and wedge-shaped but consonants appear to have been pocked first and then v-cut. There is evidence for a vowel stroke (v-cut) corrected to a consonant (pocked).
I-KER-074: Derrygarriv, Co. Kerry (CIIC 205)
Sandstone, framed diagonal cross on face. Inscription poorly preserved, up-top-down.
Carving technique(s): The cross is pocked (also pock marks on face of stone) but the ogham strokes appear to have been v-cut with flat chisel.
Baltinglass, Co. Wicklow (CIIC 49)
Granite (oatmeal, ‘softer’ granite), in two fragments which do not fit together although they appear to be from the same stone (similar drill marks where the stone is broken).
Carving technique(s): The consonant and vowel strokes are both broadly pocked, the vowels strokes approximately a quarter of the length of the consonant strokes.
Practical experiment
Two different types of stone (sandstone – soft stone, and limestone – harder stone) were used for the practical experiment to reproduce the techniques identified in the survey. Two different types of chisel were used: a point and a flat chisel. The one thing we can’t reproduce is the effect of weathering over long periods.
Findings
Many of the ogham stones examined for this pilot analysis exhibit evidence of a combination of techniques. This suggests that many ogham inscriptions were often initially roughly pocked and the resulting grooves were then either rubbed smooth (with a suitable small stone used as an abrasion tool), or v-cut with a flat chisel, leaving a distinctive line in the base of the groove. In some cases, a different technique was used for consonants and vowels, undoubtedly due to the position of vowel strokes directly on the angle being used as a stem-line (more suited to cutting at an angle with a flat chisel). The choice of technique would have depended on a number of factors including the carver’s preferred style, the stone type (and sharpness of the angle) and the available tools. Another important factor is that chisels get blunt very quickly and would need tempering in a fire frequently (Stalley 2020, 37-8). This is particularly important for v-section cutting, which requires a sharp edge.
One of the main findings of the practical experiments, also noted by Gifford Charles-Edwards in her work, is that the arris of the stone is very unsuited to carving and tends to break, particularly when using percussive techniques. This strongly suggests that ogham was invented for use on wood rather than stone.
References
Gifford Charles-Edwards, Davina. (2007): ‘The palaeography of the inscriptions’, in: Redknap, Mark, and John M. Lewis, A corpus of early medieval inscribed stones and stone sculpture in Wales, vol. 1: South-East, Wales and the English border. University of Wales Press. 77–87.
Edwards, Nancy. (2007): A Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales, Vol. II South-West Wales. University of Wales Press.
Macalister, R.A.S. (1945): Corpus inscriptionum insularum Celticarum. Vol. 1.
Stalley, Roger (2020): Early Irish Sculpture and the Art of High Crosses
Wootton, Will, Bradley, J., and Russell, B. (2013). The Art of Making in Antiquity: Stoneworking in the Roman World. http://www.artofmaking.ac.uk/explore/tools/4/Flat-Chisel.
Wootton, Will, et al. (2013). The Art of Making in Antiquity: Stoneworking in the Roman World. https://artofmaking.ac.uk/.