In the video below, wood conservation specialist Sven Habermann discusses the joinery techniques employed in making some of the more complex architectural features of the eighteenth-century interior.
Columns
The joiner had as much need to understand the orders as the mason. Columns were often called for by architects to add grandeur to entrance halls, or to frame saloon doorways. The method adopted for wooden columns was to fabricate the shaft from multiple slices of timber that together would form a cylinder. The more complex mouldings of the base were built up using the ‘brick laying’ method, which comprised several courses of blocks joined initially to form a polygon and then cut and planed into a curve on the outer side. The example illustrated below is based on columns in Russborough, Powerscourt, Leinster House, and the House of Lords (see photo at top of page).
Pediments
Pedimented doorways in timber and plaster were a common feature of the principal reception rooms of grand eighteenth-century interiors. While stone masons and carvers commonly constructed pediments for exteriors, joiners had to work on a smaller scale. Nevertheless, the task was a demanding one given the curves required to make the various mouldings – the cavetto, ovolo and cima recta. It also required understanding the structural needs of the doorcase and the kind of finish that was appropriate to the budget and materials.
The expense of mahogany forced joiners to apply highly complicated veneers when constructing interiors. The door pediment (below) is an excellent case in point as it was composed of multiples cornice mouldings which showed off the closely grained exotic hardwood to great effect. These surfaces were carefully crafted onto a pine substructure to save unnecessary use of an expensive material in places it wouldn’t be seen.
Niches
The construction of niches in the interiors of eighteenth-century houses has been little studied. More commonly we see them in stone, with their details picked out in various forms of rustication. Internally, they are commonly plastered, as seen in the entrance hall at Russborough, and their details of construction unavailable for inspection. However, the House of Lords in Dublin preserves a set of very fine oak niches that are unpainted and reveal interesting details of their construction.
The semi-hemisphere is constructed from curved segments of oak. On first glance, this seems apparent in the lobed ornament that radiates out from the centre. However, this is deceptive as it suggests to the eye that the niches is made from regular cuts of wood. In fact, this is not the case. There are twelve lobes but fourteen segments of timber and they do not relate to each other at all. The first digital reconstruction below shows the segments of the hemisphere without the lobes pulled slightly apart to make them visible. Notably, the segments are of varying sizes, suggesting that the joiners were using whatever offcuts of oak were to hand. By cutting the timber in radial form, the joiners were able to orient the direction of the grain towards a single centre point.
The next two images recreate the seamless joinery of the semi-hemisphere in which it is hard to discern the joints.
The image below shows the semi-hemisphere with the twelve lobes, which must have been carved into its smooth surface after its completion by the joiners and which impose regularity onto the overall design.
This technique likely required the carver to first draw the design onto the surface prepared by the joiners. The design is derived from the scallop-shell niche heads commonly found in antique and Renaissance Rome, where they were executed in stone, and it is interesting to see how Irish joiners and carvers of the early eighteenth century interpreted the motif. The result is quite distinctive, eschewing the boldly articulated modelling of the stone antecedants for something much more subtle.
At Hazelwood, Co. Sligo, built c. 1731, and largely contemporary with the House of Lords in Dublin, the niches in the entrance hall were made from pine and painted over.
The construction method was quite distinct from that at the House of Lords, the joiners opting for narrow cuts of timber that build up the semi-hemisphere from the bottom in a series of vertical arches. Some pieces were clearly cut from the same block and then book-matched across the x-axis.
Three of these niches were made in the entrance hall, though one of them was fabricated in a slightly different fashion (see below), with the strips laid horizontally rather than vertically, suggesting some degree of experimentation amongst the joiners. The work is unfortunately undocumented, so the fabric must tell its own story. However, the use of narrow semi-circular strips, cut with a Turning Saw, laid in layers of decreasing scale, is the first of two methods for constructing niche heads by Batty Langley in his The city and country builder’s and workman’s treasury of designs : or, The art of drawing and working the ornamental parts of architecture first published in 1740 (see below). He writes: ‘Glew all these Thicknesses, one on the other; and with a Compass, smoothing Plain, whose Arch is something quicker, than that of the Nich (sic); clear off and finish the Inside’ (p. 19).
Wainscot
The wainscoted or panelled wall was ubiquitous until the first half of the eighteenth-century. It was a common means of both insulating and decorating interiors. As explained in the video at the top of the page, wainscoting was designed to allow timber to expand and contract according to the season; panels could change size within the framework without splitting. This practical system lent itself well to the application of various kinds of mouldings, including the semi-circular bolection that projected prominently from the face of the panel it surrounded.
In many eighteenth-century interiors, dado wainscot alternated between framed and unframed panels to provide variety and rhythm as well surface articulation to the walls. The 3D viewer below provides an interactive display of a bolection panel from the entrance hall of Hazelwood, Co. Sligo, of c. 1731. Commonly pine was used, as at Hazelwood, and painted over. In grander interiors, oak (the House of Lords, Dublin) or mahogany (Russborough) wainscot was sufficiently high quality to leave unpainted. In other cases, plaster was used to imitate wainscot (the entrance hall of Castletown House).
For further analysis of wainscoting see Christine Casey’s chapter ‘”Agreeable to line in”: the wainscoted interior in eighteenth-century Britain and Ireland’ in Enriching Architecture (2023).