The Longitudinal Section of the Nile Author(s): H. G. Lyons Source: The Geographical Journal, Vol. 34, No. 1 (Jul., 1909), pp. 36-51 Published by: geographicalj Stable URL: http://www.jstor.org/stable/1777986 Accessed: 26-06-2016 14:17 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
[email protected]. The Royal Geographical Society (with the Institute of British Geographers), Wiley are collaborating with JSTOR to digitize, preserve and extend access to The Geographical Journal This content downloaded from 137.99.31.134 on Sun, 26 Jun 2016 14:17:45 UTC All use subject to http://about.jstor.org/terms 36 THE LONGITUDINAL SECTION OF THE NILE. of stone and gravel which rise on either side of the Su-lai-ho depression, suggests a likely explanation. The wall shows everywhere a uniform thickness of 8 feet, and still rises in places to over 10 feet. But that its builders knew how to make greater efforts where needed in spite of all difficulties about labour, materials, etc., is proved by the watch-towers, which are ordinarily built of sun-dried bricks of considerable strength, rising in one solid square mass to heights of 30 feet or more.