ACADEMY OP SCIENCES] CALIFORNIA 263 



. . . The determination of surface deformation in connection with this [Alaskan] earthquake . . . is . . . 

 exceptionally full and exceptionally valuable. Measurements of surface displacement are numerous, nearly 

 all of them are referred to sea level and are thus absolute instead of merely differential, and the coast line is 

 locally so intricate that the field of exact observation is areal instead of linear. The new configuration of the 

 surface is compared with the old through an area of approximately 1000 square miles, and the deformation is 

 shown to include not only faulting, with associated uplift and downthrow, but tilting and warping of a compli- 

 cated character. In the dominance of vertical displacement the tectonic characters of the Yakutat region are 

 strongly contrasted with those of the California earthquake district, where horizontal motion dominates. 



RESIDENCE AND INVESTIGATIONS AT BERKELEY, CALIF. 



Gilbert's first two summer vacations in the Sierra Nevada were followed by his assignment 

 on an investigation in California up to which a curious sequence of events had slowly led, and 

 in consequence of which a large share of his time for the last 12 years of his life was spent in the 

 Golden State. The sequence of events began, as narrated in his report, in the fifties at the 

 time of the first placer gold washing in the Sierra Nevada; the next step was the introduction of 

 high-pressure washing, or hydraulic mining as it was called, as a result of which the "tailings" 

 of the auriferous gravels on the uplands of the Sierran slope were swept in huge volumes into the 

 narrow valleys; then in 1862 came a great flood which carried the tailings in vast quantity out 

 from the valleys and spread them on the broad fluviatile plain known as the valley of California, 

 to the injury and alarm of holders of riparian lands; the protests and lawsuits then instituted 

 culminated in 1884 in a series of injunctions whereby the miners were restrained from washing 

 the tailings into the streams. This was followed by the creation through act of Congress in 

 1893 of a permanent board, known as the California Debris Commission, under which hydraulic 

 mining was prohibited except when licensed after approval of arrangements for impounding 

 the tailings; mining was thereby so greatly reduced that in 1904 the California Miners' Associa- 

 tion made the final step in the long sequence by memorializing the President of the United 

 States and asking that the National Geological Survey should "undertake a particular study of 

 those portions of the Sacramento and San Joaquin Valleys [the northern and southern parts 

 of the great fluviatile plain] affected by detritus from torrential streams" in the mountains. 

 In addition to much other work thereupon instituted under the survey, including a detailed 

 topographic survey of a large area on the fluviatile plain, Gilbert, who had long before quali- 

 tatively analyzed the transportation of debris in the third part of his Henry Mountains report, 

 was appointed to study in a quantitative way by field observation and laboratory experimentation 

 that part of the California problem which involved debris transportation. 



The greater part of the field work for this investigation was done in the years from 1905 to 

 1908. It began with observations on the uplands and in the valleys of the Sierra Nevada, and 

 it was carried across the broad fluviatile plain into San Francisco Bay, where it was eventually 

 extended to the tidal bar outside of the Golden Gate ; but after some progress had been made in 

 writing a report, the need of laboratory work was felt so seriously that the manuscript was set 

 aside until the results of experimentation could be secured. An hydraulic laboratory was there- 

 fore established at Berkeley, where Gilbert spent several years as a guest of the State university 

 and where his presence was much enjoyed. At first, however, he had not been so comfortably 

 situated. He wrote to a friend in July, 1905: "I've been two months in the State with 

 headquarters at Sacramento, which place I find so dull that I've downslidden to billiards in a 

 public billiard room. ... If I spend the winter here, the base will probably bo shifted to 

 Berkeley — where there are people I like to know"; so to Berkeley he moved the following 

 November, and for a good number of years afterwards made his home in the hospitable Faculty 

 Club on the university grounds whenever he was in California. He wrote later of his life there: 



I've a very comfortable room in the Club . . . and I'm enjoying the Club life — tho the typical Club-man 

 would find it dull. 



In return the club members enjoyed his presence greatly; when he was not absent on his 

 travels up and down the State, he had more invitations to the houses of his Berkeley friends 

 than he could accept. No need there to resort to his "knitting" as an evening occupation, 

 as he had done in the commercial metroDolis of the country. 



