02145cam a22003013u 450000100060000000300070000600500170001300600020003000700050003200800410003704000110007804100170008905000060010610000120011224500650012426400510018930000470024033600260028733700260031333800360033950000310037550800280040652012750043453400450170965300290175485600430178399900170182650383UtSlPG20260610134146.0mcr n260607r2015||||utu|||||o|||||||||||||| d  aUtSlPG 7aen2iso639-1 4aG1 aVarious14aThe National Geographic Magazine, Vol. I., No. 3, July, 1889 1aSalt Lake City, UT :bProject Gutenberg,c2015  a1 online resource :bmultiple file formats  atextbtxt2rdacontent  acomputerbc2rdamedia  aonline resourcebcr2rdacarrier  aRelease date is 2015-11-04  aProduced by Ron Swanson  a"The National Geographic Magazine, Vol. I., No. 3, July, 1889" by Various is a scientific publication written in the late 19th century. This edition of the magazine features a diverse array of articles focused on geographical topics, including detailed studies of the rivers and valleys of Pennsylvania, geological histories, and topographic models. The likely topics within encompass cartography, hydrology, and regional geological transformations that have shaped the landscape over time.  The opening of this volume introduces an article by William Morris Davis titled "The Rivers and Valleys of Pennsylvania," which sets the stage for an extensive exploration of the state's river systems. In the introduction, Davis outlines a systematic study aimed at uncovering the causes of the current river courses and tracing their evolutionary history from the prehistoric period of elevation above the sea to the present configuration. He emphasizes the importance of understanding the geological framework and previous research while outlining the general conditions of Pennsylvania's topography and its drainage patterns, preparing readers for a deeper examination of the interrelationship between the land and its waterways. (This is an automatically generated summary.)  nOriginal publication data not identified  aGeography -- Periodicals40uhttps://www.gutenberg.org/ebooks/50383  c91221d91221