Geography 777 



others, under the control of the War Department, which 

 were aided in greater or less degree by the Institution; but 

 they are too numerous to be mentioned here. 



The early explorations of Professor F. V. Hay den, which 

 were mainly geological in character, were aided by the In- 

 stitution. In 1869 Major J. W. Powell, partly at the expense 

 of the Smithsonian Institution, and partly at that of the Illi- 

 nois State University, explored the Colorado River of the 

 West, traversing it from Green River to the foot of its can- 

 ons in boats. During subsequent years he continued ex- 

 ploration of the plateau region drained by this river and its 

 tributaries, under the Smithsonian Institution, mainly by the 

 aid of direct appropriations from Congress. Finally, in 1879, 

 the organizations of Major J. W. Powell, Doctor F. V. 

 Hayden and Lieutenant G. M. Wheeler, of the United States 

 Engineer Corps, were merged into the present United States 

 Geological Survey. 



During the earlier part of this period of fifty years before 

 the general construction of railroads, the navigation of the 

 Ohio and Mississippi rivers was of the utmost importance 

 to the inhabitants of the Mississippi Valley, for it afforded the 

 only means of intercommunication between the people living 

 in the northern and southern parts of the valley of this river. 

 Furthermore, the annual inundations of the Mississippi River 

 were often the cause of great devastation to the cotton and 

 sugar fields in the lower part of the great valley, as the 

 banks of the river are lower than the river at its high-water 

 mark. Moreover, the bar at the mouth of the river was a 

 serious impediment to sea-going vessels. The Ohio and 

 Mississippi rivers were examined by Charles Ellet, under 

 the general oversight of Professor Henry, and the contribu- 

 tions of Mr. Ellet were published at various times by the 

 Institution in i849-'5o '51, and were of great value not only 

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