WEATHER AND TREES

Evening Post, Volume CXXVI, Issue 63, 12 September 1938, Page 15

WEATHER AND TREES

PROF. DOUGLASS'S WORK

Readers of the "Manchester Guardian," if no one else in this country, have read of the new science of dendrochronology, says that journal editorially. This is largely the discovery of Professor Douglass, of Arizona, a paper by whom was read to the summer school of the Men of the Trees at Oxford, and its subject (if one must attempt a'simple definition) is a development of the simple knowledge that each ring in the trunk of a tree represents one year of its growth. From his studies Professor Douglass has already made some remarkable contributions to other branches of science and learning. He has been able to tell archaeologists who have brought him pieces of timber from the sites they were excavating the exact date of the buildings to within a few years. Even more exciting is the possibility that dendrochronology will help scientists to predict with fair accuracy climatic changes in different parts of the world. NO CYCLES TO BE FOUND. Hitherto no one has been able to discover regular climatic cycles, partly because until recently no records were kept and partly (according to Professor Douglass) because there are no such cycles to discover. Now, however, periods of drought or heavy rainfall can be dated from a study of treerings in .almost any age from which timber remains and in any part of the world. Professor Douglass is still cautious, but he suggests that by "combining the work of the astronomer on all apparent changes in the sun, the physicist on all forms of radiation, the tree-ring and cyclograph man on the cycles past and present, and the meteorologist with his practical knowledge of weather changes about the world we shall have a co-operative group that can look into the future." It is from any point of view an aweinspiring thought, but what shquld we do if told that Manchester, so far from being owed a fine autumn, was entering a wet cycle of several hundred years? *