PREFACE. 



Thirty-five years ago the writer made a 

 study of the work of streams in shaping the 

 face of the land. The study included a 

 qualitative and partly deductive investigation 

 of the laws of transportation of de'bris by 

 running water; and the limitations of such 

 methods inspired a desire for quantitative 

 data, such as could be obtained only by 

 experimentation with determinate conditions. 

 The gratification of this desire was long de- 

 ferred, but opportunity for experimentation 

 finally came in connection with an investigation 

 of problems occasioned by the overloading of 

 certain California rivers with waste from 

 hydraulic mines. The physical factors of 

 those problems involve the transporting capac- 

 ity of streams as controlled by various condi- 

 tions. The experiments described in this 

 report were thus instigated by the common 

 needs of physiographic geology and hydraulic 

 engineering. 



A laboratory was established at Berkeley, 

 Cal., and the investigation became the guest 

 of the University of California, to which it is 

 indebted not only for space, within doors and 

 without, but for facilities of many kinds most 

 generously contributed. 



Almost from the beginning Mr. E. C. Murphy 

 has been associated with me in the investigation 

 and has had direct charge of the experiments. 

 Before the completion of the investigation I 

 was compelled by ill health to withdraw from 

 it, and Mr. Murphy not only made the remain- 

 ing series of experiments, so far as had been 

 definitely planned, but prepared a report. 

 This report did not incluae a full discussion of 

 the results but was of a preliminary nature, 

 it being hoped that the work might be con- 

 tinued, with enlargement of scale, in the near 

 future. When afterward I found myself able 

 to resume the study, there seemed no im- 

 mediate prospect of resuming experimentation, 

 and it was thought best to give the material 

 comparatively full treatment. It will readily 

 be understood from this account that I am 

 responsible for the planning of the experimental 



work as well as for the discussion of results 

 here contained, while Mr. Murphy is responsible 

 for the experimental work. It must not be 

 understood, however, that in assuming responsi- 

 bility for the discussion I also claim sole credit 

 for what is novel in the generalizations. Many 

 conclusions were reached by us jointly during 

 our association, and others were developed by 

 Mr. Murphy in his report. These have been 

 incorporated in the present report, so far as 

 they appeared to be sustained by the more 

 elaborate analysis, and specific credit is given 

 only where I found it practicable to quote 

 from Mr. Murphy's manuscript. 



Mr. J. A. Burgess was for a short time a 

 scientific assistant in the laboratory, and his 

 work is described in another connection. 

 Credit should be given to Mr. L. E. Eshleman, 

 carpenter, and Mr. Waldemar Arntzen, mechan- 

 ician, for excellent work in the construction of 

 apparatus. I recall with sincere gratitude 

 the cordial cooperation of several members of 

 the university faculty, and the investigation is 

 especially indebted to the good offices and 

 technical knowledge of Prof. S. B. Christy 

 and Prof. J. N. Le Conte. 



Portions of my manuscript were read by 

 Dr. R. S. Woodward and Dr. Lyman J. Briggs, 

 and the entire manuscript was read by Mr. C. E. 

 Van Orstrand and Mr. Willard D. Johnson. 

 To these gentlemen and to members of the 

 editorial staff of the Geological Survey I am 

 indebted for criticisms and suggestions leading 

 to the elimination of some of the crudities of 

 the original draft. 



While the aid which my work has received 

 from many colleagues has been so kindly and 

 efficient that individual mention seems invid- 

 ious, my gratitude must nevertheless be 

 expressed for valuable assistance by Mr. Fran- 

 cois E. Matthes in the examination of foreign 

 literature, and for the unfailing encouragement 

 and support of Mr. M. O. Leighton, until 

 recently in charge of the hydrographic work 

 of the Survey. 



G. K. G. 



