TREE-RING ANALYSIS OF TIMBERS FROM 61 LONG ACRE, BINGHAM NOTTINGHAMSHIRE
>NUTRD Report 225
Sampled November, 2003
RE HOWARD
Summary
A total of seven samples was obtained from a series of ceiling joists in the ground floor room at the east end of this building. The analysis of these samples produced a single site chronology consisting of six samples having a combined overall length of 140 rings. This site chronology was dated as spanning the years 1478 to 1617. Interpretation of the sapwood, and the relative positions of the heartwood sapwood boundaries on the dated samples, would suggest that all of them represent timbers with a felling date of 1617.
Sampling
The house at 61 Long Acre, Bingham contains several main beams and smaller timbers. These are principally two large east-west bridging beams in the ceiling of the ground-floor rooms, from which run a number of north-south common joists. There are other timbers forming wall timbers, or possibly cross-rails, or door heads, but these are smaller, and are less accessible being buried within the brickwork of the walls. Most of the ceiling timbers appear to be integral to the construction and there are no obviously reused timbers amongst them. The roof of the house has been long replaced and nothing can be said of its original form. It is known that there are additional timbers in the adjoining property which is likely to have been part of the same construction.
Thus, samples were obtained from seven different, apparently original, timbers, each sample being given the code BNG-A (for Bingham, site "A") and numbered 01 - 07. The position of these samples was recorded at the time of sampling on a drawn plan. Details of the samples are given in Table 1. In this Table, as in the plan, the trusses and their constituent timbers have been numbered and described on a site north to south, or east to west basis, as appropriate. For the purposes of the plan and Table the front of the house is taken to be facing south, the rear to be facing north.
Analysis
In the case of the seven samples from 61 Long Acre each one was prepared by sanding and polishing and the growth-ring widths of all of them were obtained by measuring. It will be seen from Table 1 that the number of rings on a couple of these samples is a little low, and that the number of rings on one sample, BNG-A06, is below the statistically reliable minimum. However, the growth-ring widths of all seven samples were compared with each other. This comparative process resulted in six of the seven cross matching with each other at relative positions as shown in the bar diagram. Because of the cross-matching between them the growth-rings of the six samples were combined at the relative off-set positions shown to form a site chronology, BNGASQ01, with a combined overall length of 140 rings. Site chronology BNGASQ01 was then compared with a wide range of reference chronologies for oak. In this process it consistently and reliably cross-matched with a high number of them when the date of the first ring of the site chronology is 1478 and the date of its last measured ring is 1617. The evidence for this dating is given in the t-values of Table 2. The list included with a few major and wide-ranging national reference chronologies. It then lists several more local chronologies. The standard of the cross-matches is well above the significant minimum t-value of 3.5.
Interpretation
Having obtained a date span for site chronology
BNGASQ01 as a whole, it is now possible to calculate the date span
of each individual sample. From this, and using the sapwood on each
sample, it becomes possible to make some interpretation as to the
felling date of the timbers represented and the construction date
of that part of the building in which the timbers are found. Normally,
and unfortunately for dendrochronology, the sapwood element of trees
is rather soft and it is most often lost, totally or at least in
part, from the timbers. This is often done either by the original
carpenters but also through woodworm, decay and general abrasion.
In the case of the samples from 61 Long Acre, however, not only
do most of the samples at least retain the heartwood/sapwood boundary
(denoted by "h/s"), but also happily one of them, BNG-A02,
retains complete sapwood. This means that the sample has the last
ring produced by the tree before it was cut down. This situation
is denoted by "C" in
Table 1 and the bar
diagram.
In this case sample BNG-A02 has a last (complete) sapwood ring date
of 1617. The relative position of the heartwood/sapwood boundaries
on the other dated samples all lie close to each other, varying
by only a couple of years. This consistency is highly indicative
of a group of trees having the same felling date, and it is almost
certain that all the timber used in this phase of the building were
felled at one and the same time, 1617.
Conclusion
Samples were obtained from seven different timbers at 61 Long Acre, Bingham. All the timbers sampled appeared to be integral to each other, and appeared to belong to the same phase of building. Six of the seven samples obtained were combined to make a very satisfactory site chronology of overall length 140 rings. One of the samples retains complete sapwood having a last measured ring date of 1617. It is highly likely that this represents the felling date of all the other timber in this phase of the building and indicates that construction took place very soon after this time.