Treee ring dating
The European oak chronology provided an excellent check of the American dendrochronologies. Ring-width patterns are determined by local environmental factors, such as temperature and rainfall.
The patterns in America could not bias the work on patterns in Europe, because the specimens came from two different local climates, separated by an ocean.
But for the specimen to be useful in extending the tree-ring chronology, the absolute calendar age of its rings must be determined.
That is, rings of the same putative dendrochronological age were found to contain the same amount of radiocarbon, and to give the same pattern of fluctuations over time.
These measurements demonstrated the basic validity of the science of dendrochronology.
Tree Ring eliminates waste by only printing as many books as ordered, but we also go one step further: we plant a tree for every yearbook sold.
The following article is abstracted from The Biblical Chronologist Volume 5, Number 1. The science of constructing chronologies from tree rings is called dendrochronology. Modern trees are known to produce one growth ring per year. (The idea that ancient trees grew more than one ring per year will be discussed below.) Therefore, by coring a living tree and counting rings from the present backwards, it is possible to determine the year in which each ring grew. The bristlecone pines in the White Mountains of California live to extremely old ages, some in excess of 4,000 years.
The more recent part of the chronology was constructed from oak logs used in various historic buildings.