CHAPTER VI.

PROJECTED OR POSSIBLE GEOGRAPHICAL CHANGES BY MAN.

Cutting of Marine Isthmuses--The Suez Canal--Canal across Isthmus of Darien--Canals to the Dead Sea--Maritime Canals in Greece-- Canal of Saros--Cape Cod Canal--Diversion of the Nile--Changes in the Caspian--Improvements in North American Hydrography-- Diversion of the Rhine--Draining of the Zuiderzee--Waters of the Karst--Subterranean Waters of Greece--Soil below Rock-- Covering Rocks with Earth--Wadies of Arabia Petræa--Incidental Effects of Human Action--Resistance to great Natural Forces-- Effects of Mining--Espy's Theories--River Sediment--Nothing small in Nature, 517