74 



PHYSICAL GEOGRAPHY. 



ment. Only a qualitative analysis was made of the water with the 

 following result: 



Carbonate of lime was present in the largest quantity. Next 

 came carbonate of soda, iron in various forms and carbonic hydro- 

 chloric acid. In smaller proportions there was present sulphuric 

 acid, magnesia, and organic matter. Only a trace of potash 

 appeared. Iron was clearly most abundant at high water. 



The temperature of the Missouri River at Dakota City during 



May, 1869, was 60° 



June, 1869, was 62° 



July, 1869, was 70° 



August, 1869, was 73° 



September, 1869, was 66° 



October, 1869, was 54° 



November, 1869, was 36^° 



December, 1869, was 35° 



The above were my own observations. The following are 

 taken from the report of the United States Signal office at Omaha 

 during 1877 and 1S7S. 



Temperature at 



bottom . 



Max. 



Min. 



77 



70 



72 



64 



6'i 



46 



45 



32 



38 



32 



52 



87 



Average 

 depth of 

 water. 

 _ Feet. 

 26 



10 

 10 

 10 

 14 



10 



July 



August 



September. 

 October.. .. 

 November. 

 December.. 



January 



P'ebruary. . . 



March 



April 



May 



June 



During several years between 1S73 and 1S79 I attempted to 

 ascertain the temperature of the Missouri at Plattsmouth, but the 

 result did not differ materially from the above. 



Though the water of the Missouri is muddy, yet when it is 

 allowed to settle and become clear, it is singularly sweet, and in 

 summer, when cooled with ice, it is even delicious. I have seen 

 barrels filled with Missouri water, in July and August, and 

 whether standing in the sun or shade, no infusoria or other minute 

 animal forms could be detected with the microscope, even after 

 a week's exposure. I have had no such experience with any other 

 river water anywhere. Probably, one reason of this is, that the 

 sediment held in suspension, by the water, carries to the bottom, as 

 it settles, all organic matter. Eventually infusoria appear in it — in 



