A dendrochronological technique was developed. It relies upon developing relative annual ring-width indices,
and identifying unusually high yearly agreement in two or
more samples. These agreements in the tree growth ring
indices are called key years. Statistical procedures are
developed for evaluating goodness of fit among sets of
A study was conducted in Surry County, Virginia which
tested methods of analyzing key-year patterns over a wide
area. Cross-dating of trees utilizing key-year patterns
from living trees and old building timbers was successfully
accomplished in Montgomery County, Virginia.
Key-year pattern data from both counties were used in
a study of the correlation of key-year patterns with the
Palmer Drought Index, to the occurrence of forest insect
outbreaks, and to forest fires. The results showed a correlation
in each case.