ACADEMY OF SCIENCES] CALIFORNIA 259 



to shocks in the future, although no one can say how soon because the rate at which a moun- 

 tain range grows is unknown. The article concluded with some salutary but unpalatable 

 suggestions : 



By the time experience has taught us this [the rate of Wasatch growth], Salt Lake City will have been 

 shaken down, and its surviving citizens will have sorrowfully rebuilt it of wood. . . . What are the citizens 

 going to do about it? Probably nothing. They are not likely to abandon brick and stone and adobe, and build 

 all new houses of wood. If they did, they would put themselves at the mercy of fire; and fire, in the long 

 run, unquestionably destroys more property than earthquakes. It is the loss of life that renders earthquakes 

 so terrible. Possibly some combination of materials will afford security against both dangers. 



The Salt Lake citizens did not like science in that form; it was too disturbing. Whatever 

 the eventual danger from earthquake might be, no one could tell how long a time would pass 

 before it would come; and in any case the removal or the remodeling of the city was out of the 

 question. Its situation in other respects was so favorable that, as to earthquakes, the citizens 

 naturally would take the chance and run the risk, for the chance might be remote rather than 

 imminent, and the risk might be small instead of great. Time enough when it comes. If 

 anyone had written a similar article, warning the citizens of San Francisco of their danger 

 because of the existence of a fault rift not far away, they also would have taken little heed of 

 the warning; it is inevitable that a city, a great city, must stand there. But after the earth- 

 quake took place and the local earth strain was relieved, the San Franciscans may well have 

 taken comfort in Gilbert's view that a city near a fault is likely, after a slip has taken place on it, 

 to be safe from further disturbance for some time to come; but whether "for many generations," 

 who can say! On the other hand, Gilbert himself must have been somewhat dismayed to see 

 that both the dangers which he foresaw for Salt Lake City had combined in a double disaster 

 for the city at the Golden Gate. 



THE SAN FRANCISCO EARTHQUAKE 



Gilbert's unusual capacity for the popular exposition of scientific subjects has already been 

 alluded to. It is well exemplified in a general account of the San Francisco earthquake " which 

 he prepared shortly after its occurrence, the first paragraph of which is written in a singularly 

 objective style. 



It is the natural and legitimate ambition of a properly constituted geologist to see a glacier, witness an 

 eruption, and feel an earthquake. The glacier is always ready, awaiting his visit; the eruption has a course to 

 run, and alacrity only is needed to watch its more important phases; but the earthquake, unheralded and brief, 

 may elude him through his entire lifetime. It had been my fortune to experience only a single weak tremor, 

 and I had, moreover, been tantalized by narrowly missing the great Inyo earthquake of 1872 [in southeastern 

 California] and the Alaska earthquake of 1899. When, therefore, I was awakened in Berkeley on the eighteenth 

 of April last by a tumult of motions and noises, it was with unalloyed pleasure that I became aware that a 

 vigorous earthquake was in progress. The creaking of the building, which has a heavy frame of redwood, and 

 the rattling of various articles of furniture so occupied my attention that I did not fully differentiate the noises 

 peculiar to the earthquake itself. The motions I was able to analyse more successfully, perceiving that, while 

 they had many directions, the dominant factor was a swaying in the north-south direction, which caused me to 

 roll slightly as I lay with my head toward the east. Afterward I found a suspended electric lamp swinging in 

 the north-south direction, and observed that water had been splashed southward from a pitcher. These notes 

 of direction were of little value, however, except as showing control by the structure of the building, for in 

 another part of the same building the east-west motion was dominant. 



In order to make the most of this rare opportunity, he left the fire to the firemen, the 

 injured to the doctors, the homeless to the charitable, and devoted himself as a geologist to the 

 geological phenomena, especially the displacements along the trace of the old fault plane on 

 which the earthquake originated. After giving an account of many striking instances in which 

 the horizontal displacement of the earthquake is apparent, he expresses the hope that studies 

 should be made by engineers and architects regarding the safer construction of buildings, so 

 that — 



the new city should be earthquake proof. . . . Timidity will cause some to remove from the shaken district 

 and will deter others who were contemplating immigration, but such considerations have onh' temporary in- 



• An investigation of the San Francisco earthquake. Pop. Sci. Monthly, 1 sii, 1906, 97-115. 



