Last evening Mr. Samuel Eliot read an essay on "The Relation of Forests to Rain-fall and Water Supply," before an appreciative audience in Sever 3. Mr. Eliot followed out a line of argument which was based upon the facts of observation rather than on a plausible theory. The lands of the Mediterranean were once called the gardens of the world, but to day these once fertile fields have become arid deserts. What has been the cause of the great climatic change, whereby these countries have lost their former power to produce large crops, and no longer are able to support as large a population as formerly? A number of cases where water-courses and lakes have decreased in volume while the clearing of forests was being carried on, and which resumed their former size upon the cessation of the clearing were cited. The destruction of the forests in this country and in Europe has been so great that many have estimated that, if the present wholesale cutting is continued the Rhine, Elbe and other important streams will become unnavigable. The evidence of history is so marked that there can be no doubt but that the earth's crust is becoming deeper and that the cutting of forests has aided in this process. Governments have seen this and have established forestry bureaus for the preservation of the forests.