10 EAETHQTJAKES ON THE PACIFIC COAST 



the character of the shock, whether a tremor or an undulatory 

 motion, etc., and whether you yourself or others had any clear im- 

 pression as to the direction in which it was moving, the facts 

 upon which this impression was based, and whether people agreed 

 as to the direction. 



7. Which number on the Rossi-Forel scale of earthquake inten- 

 sity best expresses the intensity of the shock in your vicinity? 



8. Give, also, any further particulars of interest, whether they are 

 from observation or from hearsay. 



If a chandelier was noticed to swing, describe it, and state the 

 direction and amoimt of swing. If pictures swung, state direction 

 of wall, and whether pictures on other walls at right angles to the 

 first were also put in motion. If doors were closed or opened by 

 the shock, state the direction of the wall in which they are set. 

 If a clock was stopped, give the exact time it indicated (and any- 

 thing known, as how fast or how slow it was), its position, the 

 direction in which it was facing, and the length of the pendulum. 

 If any changes occurred in the ground, such as depressions or ele- 

 vations of the surface, fissures, emissions of sand or water, describe 

 them fully. Mention any unusual condition of the atmosphere; 

 any strange effects on animals (it is often said that they will feel 

 the first tremors of a shock before people notice it at all); char- 

 acter of damage to buildings, general direction in which walls, 

 chimneys, etc., were overthrown. Springs, wells, and rivers are 

 often noticeably affected even by slight shocks, and any informa- 

 tion in regard to such changes will be valuable. 



9. Name of the writer. 



Note. — In replying to these questions, they need not be re- 

 peated; but the answers should be numbered to correspond to the 

 questions." 



The lists which follow give recorded earthquakes in their chrono- 

 logical order. It is desirable to arrange the statistics in various 

 ways — by years, by months, by seasons, etc. — in order to exhibit 

 any periodicity there may possibly be in the phenomena. It is a 

 favorite hypothesis that shocks follow in cycles; and this is true 

 of some regions, apparently. 



The tables A, B, C were prepared for the first edition of this 

 book, and are here reprinted without change. The addition of the 

 data since 1887 would not alter the conclusions to be derived from 

 them. 



