756 



SCIENCE. 



[N. S. Vol. XXIII. No. 593 



THE CALIFORNIA EARTHQUAKE AT URIAH. 



The earthquake which, wrought such de- 

 struction in San Francisco and Santa Eosa, 

 on April 18, was very severe in Ukiah, 160 

 kilometers (96 miles) northwest of San Fran- 

 cisco. Many chimneys were thrown down 

 from two-story buildings but cottages escaped 

 without injury. One new brick store build- 

 ing, just nearing completion, was so badly 

 cracked and thrown out of plumb that it is 

 necessary to tear it down. 



At the Latitude Station no damage what- 

 ever was done although the shaking was the 

 most severe ever experienced by the writer. 

 Dishes rattled, milk was spilled from pans 

 but little more than half full, and fowls and 

 other domestic animals were very much 

 perturbed. There were a series of shocks and 

 reliable estimates of their duration vary from 

 twenty seconds to one minute. The 'general 

 direction of the wave seemed to be from south- 

 west toward the northeast, but others report a 

 difFerent direction. The Ukiah Valley is sur- 

 rounded by mountains of considerable altitude 

 and it is probable that some of the shocks felt 

 were from waves reflected from the mountains. 

 Hence it is that the earthquake is generally 

 spoken of as a ' twister.' 



The observatory clock was not stopped but it 

 lost six seconds during the disturbance, which 

 is equivalent to being stopped for that 

 length of time and then set to going again. 

 The observatory roof is built in two sections 

 which roll upon horizontal tracks, east and 

 west, giving an opening for observation of 

 about 1.8 meters. When closed the two parts 

 are fastened together by means of a hook and 

 eye such as are used on screen doors. The 

 hook rests in a horizontal position and the 

 bend of the hook in a meridian plane. The 

 effect of the earthquake was to unfasten this 

 hook and open the roof to a width of about 

 twenty centimeters, my recollection being that 

 the eastern half was moved about twice as far 

 as the western. The pier upon which the 

 zenith telescope rests is apparently not dam- 

 aged but the telescope was thrown considerably 

 out of adjustment. It was out about fifteen 

 seconds of arc in azimuth and the vertical 



axis was out in both directions, but not much 

 more than sometimes results from extreme 

 changes in temperature. 



The first series of shocks was followed by 

 three lighter ones and the observed data for 

 each are as follows : 



Pacific stand. Time Duration. Direction. Intensity. 



1906 April 



18a 5h 13m 00s A.M. About 40s S.W. toN.E. Severe. 



18 10 4 39 A.M. " 10 S.W. toN.E. Medium. 



18 11 36 00 A.M. " 30 S.W. to N.E. Ligllt. 



20 12 30 63 A.M. Very slight. 



The times are correct within two or three sec- 

 onds. 



I was in the observatory at the time of the 

 second series of shocks, at lOi" 4™, and per- 

 ceived the effect of the movement in the strid- 

 ing level (east and west), of the zenith tele- 

 scope. The bubble oscillated over about two 

 divisions of the level. The value of one 

 division is 2".2 and as the distance between 

 the east and west leveling screws of the in- 

 strument is about 42 centimeters, the disturb- 

 ance produced in the bubble was equivalent 

 to the effect of raising and lowering one of the 

 leveling screws by 0.0005 centimeter. This 

 shock was felt very distinctly and it is prob- 

 able that the north and south component of 

 the motion was much greater than the east 

 and west one. 



The fourth shock was not felt at all. It 

 was detected during the progress of latitude 

 observations by a movement of the bubbles of 

 the latitude levels. The oscillation (north 

 and south) was about one half of one division, 

 and the value of one division is 1.0. 



Sidney D. Townley. 



International Latitude Obseevatoky, 

 Ukiah, Califoenia. 



SCIENTIFIC BUILDINGS AND COLLECTIONS 

 AT STANFORD UNITERSITY.'^ 



The scientific laboratories and collections 

 at Stanford University were but slightly in- 

 jured by the recent earthquake in Oalifornia. 

 The buildings containing the departments of 

 physiology, botany, zoology and entomology 

 are uninjured structurally, and the apparatus 



' We print this note, although it reduplicates to 

 a certain extent the information communicated to 

 us last week by President Jordan. 



