AUTOMATIC ACTION OF "WATER 199 



the face of the continents (except Avhen diastrophy, eolation, vulcan- 

 icity, or glaciation have temporarily intervened) in harmonic combina- 

 tions of curves stretching from crests to coasts in graceful sweeps of 

 which each part is adjusted to all others and also to ready movement of 

 the waters — the true Hogarthian lines of beaut}^, as Yan Hise and others 

 happily hold. 



SPECIAL FUNCTIONS OF MOVIN& WATEE 



The moving stream-water makes its bed and eventually shapes its 

 valley through three primary processes, namely, (1) erosion, (2) trans- 

 portation, and (3) deposition; and each of these three processes is 

 complex : 



1. Erosion (neglecting the more passive processes of disintegration, 

 weathering, etcetera) may be considered as the general process whereby 

 the earth matter is removed by running water from its original loci; it 

 comprises (a) solution, in which earth salts are more or less completely 

 dissolved; (6) w^ashing, in which finer and softer materials are still 

 further comminuted and softened and floated away; and (c) corrasion, 

 in which firmer materials are cut and scoured by the impact of solid 

 particles dropped or driven 1)y the moving water. 



2. Transportation may be regarded as the general movement of earth 

 matter seaward by streams; it comprises carriage of material (a) in solu- 

 tion, (b) in suspension, and (c) in what may be denoted saltation, the 

 three processes corresponding fairly vsath those of erosion, since the dis- 

 solved rock matter is carried in solution, much of the washed materials 

 (together with the finer corraded particles) are carried in suspension, 

 while the coarser particles due to corrasion (including crushing, grinding, 

 etcetera) and to washing move forward at ever varying rates in saltatory 

 fashion, the variable or leaping movements arising largely in combinations 

 of friction Avitli inertia, as discussed long ago by Hopkins and more 

 recently by Le Conte, Gilbert, and others. 



3. Deposition may be viewed concordautly as the general process 

 whereby the transfer of earth matter is completed ; it comprises (a) pre- 

 cipitation, typically of matter contained in sohition on contact with sea 

 water; (h) sedimentation, typically the settling of suspended matter on 

 slackening of current; and (c) grounding, or the more or less temporary 

 dropping and lodgment of particles carried in saltation, typically in sand 

 bars, natural levees, gravel beds, etcetera. 



All the main and minor processes blend and measurably alternate in 

 ordinary stream-work, and all are dependent for their eflSciency on a 

 variety of factors, of which those most commonly recognized are gravity 



