"Trees perspire profusely, condense largely, and check evaporation so much, that woods are always moist: no wonder therefore that they contribute much to pools and streams. That trees are great promoters of lakes and rivers appears from a well known fact in North-America; for, since the woods and forests have been grubbed and cleared, all bodies of water have much diminished; so that some streams, that were very considerable a century ago, will not now drive a common mill."