THE WORK OF RUNNING V/ATER. 



107 



The following table » gives the percentage of material carried in suspension 

 by various rivers: 





.S 



^11 







:m 



3edi- 

 ches 

 over 

 a. 





°d ^ 



O w 







OjCO g. 



"^ R (J 



River. 



^S 



<''i 



"2 c^ 



Total Tons 



'0 >, 





•5=-§^ 





II 





Annually. 



OS 



■II 



eight in 

 Column 

 ment wi 

 of One 

 Mile. 



lickness 

 ment i 

 if Spre 

 Drainag 





Q 



S 





p^ 



W 



H 



Potomac 



11,043 



20,160 



5,557,250 



l: 3,575 



4.0 



.00433 



Mississippi 



1,244,000 



610,000 



406,250,000 



1: 1,500 



241.4 



.00223 



Rio Grande . . . 



30,000 



1,700 



3,830,000 



1 : 291 



2.8 



.00116 



Uruguay 



150,000 



150,000 



14,782,500 



1 : 10,000 



10.6 



.00085 



Rhone 



34,800 



65,850 



36,000,000 



1: 1,775 



31.1 



.01075 



Po 



27,100 



62,200 



67,000,000 



1 : 900 



59.0 



.01139 



Danube 



320,300 



315,200 



108,000,000 



1: 2,880 



93.2 



.00354 



Nile 



1,100,000 



113,000 



54,000,000 



1: 2,050 



38.8 



.00042 



Irrawaddy ... 



125,000 



475,000 



291,430,000 



1 : 1,610 



209.0 



.02005 



Mean 



334,693 



201,468 



109,649,972 



1 : 2,731 



76.65 



.00614 



«vas 



Organic carbon 99 part in 1,000,000 of water. 



Organic nitrogen 22 " ' ' " 



Ammonia. 50 *' " " 



Nitrogen as nitrates and nitrites .... .07 '' " '' 



Chlorine 6 . 30 parts in ' ' 



Total solids 39.50 '' *' 



A comparison of the composition of rain-water with that of springs and rivers 

 gives some idea of the solvent work of water. From a study of the water of 

 nineteen of the principal rivers of the world Murray has compiled the following 

 table' showing the amount of mineral matter in average river water: 



MATERIAL IN SOLUTION IN ONE CUBIC MILE OF AVERAGE 

 RIVER WATER.* 



Constituents. Tons in a Cubic Mile. 



Calcium carbonate (CaCOg) 326,710 



Magnesium carbonate (MgCOs) 112,870 



Calcium phosphate (CagPA) 2,913 



Calcium sulphate (CaSOJ 34,361 



Sodium sulphate (NaaSOJ 31,805 



* Babb. Science, Vol. XXI, p. 343. 1893. 



^Quoted by Mason. Water-supply, p. 204. 



'Sot. Geog. Mag., Vol. Ill, p. 76. 1887. 



^ Acids and bases combined according to the principles indicated by Bunsen. 



