NATURAL WATERWAYS IN THE UNITED STATES.^ 



Review of Recent Progress and Present Tendencies. 



By Lt. Col. Wxt. W. Haet.s, 

 Corps of Engineers, U. S. Army, 



[With 9 plates.] 

 PROBLEMS PRESENTED. 



In all countries where interior waterways are used for navigation 

 to an}^ marked extent, there arise many complex problems, of which 

 the most important are : First, the physical, based on the character- 

 istics of the river, such as its discharge, slope, the permanency of its 

 bed and banks, and the feasibility of treatment so as to make it 

 suitable for navigation; second, the economic, based on the charac- 

 ter and expense of the work necessary for such a purpose, together 

 with the return on the investment that can be obtained. 



These two classes of problems appeal in a more or less forcible 

 Avay to different interests; the first more properly to the river engi- 

 neer, and the second to those responsible for supplying funds — in 

 the case of Government work, to Congress. Within comparatively 

 recent years, the work of building channels has been more and more 

 carefully studied in order to combine the best practicable solutions 

 of all these problems, so that now no plan for a proposed river work 

 is complete until the subject has been practically exhausted, on both 

 the physical and economic sides, by the engineers proposing the plan. 



STAGES OF INLAND-WATERWAY DEVELOPMENT. 



Interior navigation in all countries has passed through several 

 well-defined stages. The first stage antedates the use of steam as a 

 propelling power, commencing with the time when the only means 

 of transportation was by animals or animal-drawn Aehicles, either 

 wugons and carriages, canal boats, or pack animals. This limited 

 source of power restricted transportation lines to highways and 

 canals. It was not until the use of steam was successfully applied to 



1 Paper presented at a meeting of the International Engineering Congress, 1915, at 

 San Francisco, September 20-25, 1915. Reprinted by permission of the author from 

 the Transactious of that Congress. 



545 



