Crossing Conundrum

So, I've spent the day drawing the plan of the church of Holy Trinity Priory, York as it may have been c1450 based on the remaining evidence.

And, I've run into a problem but also an excellent opportunity to demonstrate how the act of reconstruction can actually drive forward research on historic sites, or at least uncover major gaps in our current understanding.  This happens routinely, and it's convenient that it has happened here.

So, the problem:  the crossing.  Nothing joins up.

Help!

The church was cruciform in plan with four arms or wings extending east (the chancel), west (the nave), north and south (the transepts).  While only the core of the nave survives today, enough evidence remains to be able to sketch the outline of the medieval church.  At the turn of the last century a Holy Trinity parishioner and antiquarian, Walter Harvey Brook, undertook a series of excavations on the site in advance of restoration works.  The excavations were remarkably systematic for their time and Brook took copious, detailed notes and photographs, as well as produced three notebooks full of drawings.  Brook's excavations revealed the plan of the medieval church in much more detail than is visible today.  His work is the bedrock upon which later studies of the site are based.

Two later studies in particular are very important: the Royal Commisison report in 1972 and David Stocker's article on the priory in the BAA volume on Yorkshire Monasticism in 1995.  Of the two, Stocker is the most reliable regarding the building.

The result of all of this careful work is a series of reconstruction plans of the medieval church.  Using these plans, I should be able to reconstruct much of the interior arrangement of the church.

So you would think.

Brook's plan

The Royal Commission's plan

Stocker's plan

But, as is often the case, there are gaps in understanding which pose serious challenges for reconstruction but which have gone unnoticed during the composition of academic articles on the site.  Reconstruction forces the researcher to think systematically, considering practical issues of geometry and construction techniques.  When a reconstruction exists simply in the mind it is easy to miss major problems.  Add to this the fact that we must rely on work subject to all of the unrecorded little particulars of recording on site while Brook's excavations were conducted.  And we cannot directly investigate Brook's evidence (archaeology destroys its own evidence as a matter of course).  You begin to see that we can get into trouble easily.

In the plans all arms of the church join up neatly at the crossing, naturally.  But you can see that there are differences in these.  Brook's is a bit of a fantasy coloured by what he wanted to see more than what he actually saw, and this is acknowledged by Brook himself.  In the drawing he has crossed out many features.  It is very much a sketch of hypotheses rather than a finished site drawing.  Brook's more detailed notes and drawings are much more reliable.  The Royal Commission's plan carries with it all of the weight and authority of the Commission, communicated in its sure, clean lines which do not leave room for uncertainty (except in the dotted lines indicating unexcavated, assumed, features).  Stocker's plan differs from this significantly in that he does not include a western aisle to the north transept (which I believe) but also in many subtle features as well, particularly in the placing and extent of Brook's excavated features and the still standing line of the south wall of the chancel.

The real fight here is between the Commission and Stocker.  Here, I am very much in Stocker's corner.  The Commission shows much of the line of the walls of a western aisle of the transept as excavated 'fact' based on Brook.  But Stocker checked the original source and found that he did not excavation in this location because of the cemetery, which was still operational at that time.  They also appear to have misread Brook's notes in siting his excavated transept pier base in the west rather than in the east, as Stocker shows.  Also, the Commission plan only shows a small fragment of the northeastern pier of the crossing, tracing the eastern crossing piers' full extent as conjectural.  Stocker shows that both of these piers seem to have been fully excavated by Brook.  Both plans agree, at least, on the positions of piers in the chancel's southern arcade and the relative position of the south chancel aisle wall.  But they differ significantly in the extent of that wall.

So what, then?

As drawn by both Stocker and the Commission, the plan of the church reveals a building that could not have functioned structurally in the way everyone from Brook to me (until today) have assumed, i.e. that the chancel aisles were vaulted.  Vaulting must have existed somewhere on the site because a handful of vault rib voussoirs survive.  The first pier east of the crossing should line up with the north-south walls of the transepts.  If they do, then the entire length of the aisles can be divided into convenient rectangular bays which are simple to cover with a quadripartite ribbed vault.  But, in both plans this is not the case.  The lines of the walls end in the aisle mid-bay.  It is still possible to vault these bays, but the vaults would be very awkward - more awkward than the vaulting in the same bays in York Minster.  Not having a vault in this bay would leave the remaining three bays to the east oddly alone in their vaulting, incomplete.  If an aisle is vaulted this usually runs the length of the aisle.

In fact, you can see that the medieval builders encountered this problem and seem to have found a solution by extending a short stub of wall eastward from the eastern crossing piers, to push the position of the arcade respond into line with the wall of the transept.  But in the two plans, the alignment is still poor.

The problem is that neither plan is clear about their evidence, and the evidence they do have conflicts.  What is known is the position of the southern wall of the chancel as well as the line of its southern arcade, giving the width of the chancel aisle and its length.  What is not known is the width of the transept aisles.  In the Commission plan there does not appear to be any evidence for the width of the transept aisles as they show them.  In Stocker's plan the end of the southern transept's eastern wall has been assumed to be marked by the western end of the surviving chancel south wall.  This makes the awkward corner and the structurally problematic crossing and adjoining aisles.  But in the Commission plan the south wall of the chancel does not extend as far west.  In fact, it seems to end in line with the first pier east of the crossing.  This would place the eastern wall of the transepts in perfect alignment for vaulting but make very wide transept aisles with an unusually wide western arch in the chancel arcades.  But the Commission does not seem very sure about its placing of the eastern crossing piers.

So, who is right?  And how do I finish my drawing?  I cannot re-excavate, and I'm not sure Brook left anything for me to uncover even if I did.

I think I'll take my tape measure and knock on the rectory door, ask if I can measure their garden wall (which is the south wall of the chancel).

If you want something done right...