Proceedings 17        March 1990        the Danson Room at Trinity College, Oxford, following the Annual General Meeting of the Society

CARPENTRY IN MEDIEVAL ARCHITECTURE: an illustrated talk by Mr Julian Munby (member of SHMTS)

———————

After the President’s introductory remarks, Mr Munby opened his subject by recalling that the steam engine, the motorcar and the aeroplane in their early forms, all employed timber to a greater or lesser extent. In the medieval period only the astrolabe and the mechanical clock depended almost exclusively on metal, while timber was predominant even in much architecture, being superior to stone in its capacity to withstand tensile forces. However, medieval timber construction was little researched compared with architecture in stone which had been intensely studied thanks in large part to the Gothic: revivalism of the last century. It was of course the sole material used for scaffolding, ladders, cranes, centring for some arches and vaults but also had major structural functions as in frame construction and in shoring timbers for harbour walls etc., as at London’s tidal wharf.

Managed woodlands provided a renewable resource with rotation of coppiced under wood and timber standards (1). Large trees might have to be acquired by gift, purchase and even theft, from royal or lords’ forests (2). Carpenters chose the tree(s) which were then felled and worked shortly before use. Illustrations show them working timber on low trestles using the side axe, which gave a true straight edge, the adze being little used in comparison. Special commissions such as the Bishop of Exeter’s throne might call for seasoned timber--it was in fact left to soak in a millpond--but most wood seems to have been worked green (fresh timber tightened as it dried). The adaptation of the crank principle to the small augur to produce the familiar brace and-bit, possibly as late as 1400, was the great innovation in a tool kit essentially unchanged since ancient times

Carpentry in building was a process of prefabrication. The classic constructional system was the mortice-and-tenon jointed timber frame, raised a storey at a time and topped with an independent roof structure of prefabricated trusses. No doubt designs were drawn up, if only to accompany contract specifications (an early 16th c. example was in the Bishop of Worcester’s Register), but construction took place in a framing yard where timbers were worked side by side and checked to each other as the frame unit or roof truss developed. Numerical marking systems made it possible to dismantle the units for re-assembly on site.

Using an intriguing sequence of slides, Mr Munby next traced developments in timber roofing: in the CLASSICAL tradition from the 6th century Mount Syon monastery, Sinai, to examples by Palladio in the 16th century who influenced Inigo Jones and Wren in the 17th; the Northern or RAFTER tradition; the PURL1N roof with kingposts, possibly introduced from France, crown posts, an English invention, double framed roofs with principal trusses and so to the classic: late medieval roof. Aisled barns (e.g. Great Coxwell, 1310) and halls called for different solutions and clearing away the aisle posts was the source of much ingenuity, including the raising of them~ on tie beams. A notable timber roof was the bishop’s kitchen at Chichester (1290). The hammerbeam roof, originating in late 13th century (possibly in England) culminated, together with the arch-brace, in Westminster Hall. Cantilevering was spectacularly used in such great roofs as the Octagon Lantern, Ely (1320s) and also to reduce the span of the chapter house at York Minster

During the middle ages, Europe’s carpenters also moved towards standard procedures in house building. The practise of projecting upper stories in urban houses probably originated in the Low Countries (the earliest English example dates from 1306). The use of standardized numbered parts made it possible to build such ‘jettied’ houses in the congested space of a medieval town (e.g. Queen’s Street, Salisbury 1306), the frame often going up in a day. England's Wealden house represented similar standardization in rural house building.

Wood was also much used in machinery, many mills having wooden cogging as well as frame and structural parts. Cranes, such as the famous one at Luneberg (3) were largely timber built, as were war machines, carts and of course ships. Even a rapid survey, the speaker concluded, revealed the extraordinary versatility of timber and of the men who worked it. Considering its central role in medieval technology it had, he felt, been curiously ignored.

The President thanked the speaker for his comprehensive and wide-ranging talk and following questions from the floor drew the meeting to a close.

(1) Also note The Medieval Forest--Its People and T2chnology, Bechmann, SHMTS Proceedings 4 Oct 1987.

(2) Clause 31 of Magna Carta 1215 provided that neither the king nor his agents should take for our castles or for any other work of ours, wood which is not ours, against the will of the owner ...’.

(3) See Animal Powered Machinery in the Medieval Period, Major, SHMTS Proceedings 5, Nov ’87.

Summary by GSH