Ridpath's history of the world; being an account of the ethnic origin, primitive estate, early migrations, social conditions and present promise of the principal families of men .. . rthan the springrains of each yearin our presentclimatic condition to note the largequantities of solid matter that are carrieddown into our river currents. Doubtless,in the times of the formation of riverbeds, when the overwhelming waters,new melted from the glacial spurs, wererushing along the surface of valley landsto seek a permanent channel, theamount of solid material cut away, mixedwith the waters and borne
Ridpath's history of the world; being an account of the ethnic origin, primitive estate, early migrations, social conditions and present promise of the principal families of men .. . rthan the springrains of each yearin our presentclimatic condition to note the largequantities of solid matter that are carrieddown into our river currents. Doubtless,in the times of the formation of riverbeds, when the overwhelming waters,new melted from the glacial spurs, wererushing along the surface of valley landsto seek a permanent channel, theamount of solid material cut away, mixedwith the waters and borne onward in avolume of slush to the sea, was vastlyin excess of anything of like kind which now falls under our to the present day there are largerivers whose sloppy floods bear down aquantity of solid matter so great as tobuild up large sand bars and gravelbanks in a comparatively short space oftime. It is, therefore, reasonable to supposethat in the early age of the Mississippithe annual deposits at the influence of thedelta were much more ex- ^e dUu?STe °ftensive than they have within the historical period. Onthe other hand, however, a counter-. DELTA OF THE MISSISSIPPI. vailing circumstance must be notedwhich has tended strongly to prolongthe period of formation in alluvialdeposits. This is the fact that when theprimitive rivers were still swollen andmuch mixed with solid materials thecurrent was so heavy as to bear thosematerials far out to sea. The strongprobability is that in the case of theMississippi the earlier and heaviermasses of solid matter were borne outby the immense floods and deposited in 96 GREAT RACES OF MANKIND. the bottom of the gulf, so that it maywell be doubted whether the larger con-tribution of solids in the earlier ages wasnot actually unfavorable rather thanfavorable to the rapid building up ofthe delta. Two additional facts should be notedin connection with this particular sub-other estimates ject. The first is thatconf
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Keywords: ., bookcentury1800, bookdecade1890, booksub, booksubjectworldhistory
