If this were so, the width of the annual growth rings would show changes in synchronism with the sunspot numbers.
This is most impressive and makes dendrochronology the main dating method for structures containing oak timber.
Year by year the trees throughout the region produce a similar pattern of wide and narrow rings in response to the weather changes.
It is this pattern that allows the accurate dating.
In a 'poor' growing season the trees all respond so that only a very narrow growth ring is formed.
In more typical growing seasons a ring of intermediate width is produced.
None is infallible and before embarking on an extensive dating survey, due thought must be given to what might be achieved and which methods might be the more successful. Whilst earlier types of wooden joints may be copied in later buildings and earlier styles may be reintroduced in later periods to confound the conservationist or historian, any reuse of older materials should become obvious by the use of the chronometrical methods described here.
The incorporation of ancient bog oak into a building, no matter how intricately carved or jointed, would immediately become obvious to the chronologist, as would timber renovations.
His laboratory is still one of the leading centres in world dendrochronology.
It was not until 1939 that the science was taken seriously in Europe, mainly through the efforts of Professor Huber in Germany, and not until after World War II that such studies became established in the UK.
Almost certainly the century or portion of a century when it was built may be assigned with some certainty.
However, as more and more work is done and increasing numbers of structures with complex constructional phases are encountered, the general features may not be sufficient to give the accuracy in dating that is currently required.
The pattern of ring widths on a specimen taken from a building is matched, using a computer with a 'master chronology' often several centuries long for the particular area.