President's Address. 53 



expectation. In some instances such improvements when made in 

 a large measure will be directly in opposition to the great laws of 

 nature whiqh govern rivers. So few people apparently understand 

 the foundation principles of rivers that, after all, mistakes of the 

 kind above alluded to need not be surprising. It is desired, there- 

 fore, in the short time allotted to this paper to point out a few of 

 the principles of nature governing rivers, to show the shortcomings 

 of some of the schemes already adopted and of others proposed for 

 adoption in various places, and possibly to make a few suggestions 

 which may be of assistance to those engaged in this exceedingly im- 

 portant undertaking. The great fundamental laws of river erosion 

 and river processes are plain and simple and easy to understand. 

 Probably on account of their simplicity many people have failed 

 to understand them or to believe in them when pointed out, insist- 

 ing, as seems to be the part of human nature, that such processes 

 must be more complicated and more mysterious. 



It is only within the last half century, so far as I can learn from 

 history, that any one has fully comprehended the principles govern- 

 ing the life history of a river. I need only refer to the well-known 

 fact that when Captain Eads first proposed the improvements at 

 the mouth of the Mississippi river, commonly known as "Eads' 

 Jetties," it took him years to persuade our national legislators that 

 such a scheme would accomplish the desired results, even if prop- 

 erly executed. It is an interesting fact of history that practically 

 all the great engineers of our nation scoffed at the idea and insisted 

 that his scheme was utterly impracticable, and, therefore, should 

 not be attempted. And to-day I may say — and I do it in a spirit 

 of humility and not one of criticism — and to-day I may say it is 

 one of the greatest surprises to find how large a proportion of the 

 practical engineers of our country have failed to grasp the funda- 

 mental principles of river action and put into execution improve- 

 ments and precautions based upon them. 



RIVER PROCESSES. 



Every stream of water, no matter where situated on the surface 

 of the earth, obeys the same fundamental laws that govern every 

 other stream. It matters not where one goes to study this subject, 

 data can be gathered in all parts of the world. Let us suppose 

 that we are studying a stream in a mountainous district where the 

 inclination of the surface is comparatively great, say at least 100 

 feet to the mile. During rainy weather the stream in question 

 will have a fair amount of water and the tendency will be for it to 

 cut its channel deeper. The cutting process is carried on in part 



