Footnotes to Dendrochronology (Tree-Ring Dating) of Panel Paintings

1. Twenty paintings by Lucas Cranach the Elder have now been reported as coming from the same beech tree (Klein, 1994 and pers. comm.) It is reasonable to assume that they must have been painted at approximately the same time.
2. Dr. Klein, who has probably analyzed more panels than everybody else combined, now reports (Nov. 1994) that he uses a minimum of nine sapwood rings for Eastern Europe and seven sapwood rings for Western Europe in estimating the earliest possible felling date.
3. Dr. Klein informs me that this textbook example is flawed since almost all the published sapwood estimates apply to average ring-counts for the majority of samples rather than to the extremes for individual trees, and he finds greater variability in Western Europe. A final heartwood ring of 1651 plus a minimum of 7 sapwood rings for Western European oak = 1658, plus a minimum drying time of 2 years = 1660. A final heartwood ring of 1651 plus a minimum of 9 sapwood rings for Baltic oak = 1660, plus a minimum drying time of 2 years = 1662. Both dates are therefore within Rembrandt's lifetime. Moral #1: beware of averages. Moral #2: beware of textbook examples. Moral #3: never accept a fee for providing dendrochronological information.
4. The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology is supported by the National Endowment for the Humanities, the National Science Foundation, the Malcolm H. Wiener Foundation, the National Geographic Society, the Samuel H. Kress Foundation, the Wenner-Gren Foundation for Anthropological Research, and individual Patrons of the Aegean Dendrochronology Project.