378 REPORT OF THE CALIFORNIA EARTHQUAKE COMMISSION. 
Another interesting question to which the testimony gives rise is: How do such vibra- 
tions reach any locality in advance of the shock? The seismic waves traverse the earth’s 
crust very much more swiftly than sound-waves do the air, so that it is a physical impos- 
sibility for sound-waves generated in the air above the seat of disturbance to outreach 
them. The vibrations observed as sounds must, therefore, be transmitted to the at- 
mosphere by tremors of the ground which precede the larger waves, and which are not 
otherwise perceptible to the senses ordinarily. These doubtless correspond to those 
phases of seismic movements which are recorded by delicate instruments and are known 
as ‘preliminary tremors.” 
Noises heard at the time of the shock. 









































Locality. Reporter. Observer. Kind, direction, time of noise, ete. 

Ferndale.......- AS WiablackburngiSamen.ss. soe Accompanying the quake was a rumbling, 
roaring sound. 
COVelot tress E. 8. Larsen .... | Large proportion | Roar just preceding earthquake shock. 
of residents.... 
Fort Bragg......+ O. Fa Barth....- AMS. sae ees The wave traveled SW. and a roar ac- 
companied it. 
Mendocino ...... Wm. Mullen..... SaMe sac. de. fee Unusual rumbling sound like distant thun- 
der, preceding shake, being loudest at 
commencement of disturbance. 

Albionger een ee Ji CoVIGraniss ans aI Oia is/o ete tele Roaring noise like heavy fall of hail com- 
ing from ocean to the west. 
Point Arena..... W. W. Fairbanks | Not named...... Heavy roaring sound preceded the shock. 
Point Arena Light- dO. Ave a. Keeper.ssssceecee Blow came quick and heavy, accompa- 
NOUSG@2 neater ae nied by heavy report. 
Upper Lake..... C. M. Hammond A roaring noise past off to SW. 
GO tes ce eee ire CO ieee Workmen. «. 3.5... A noise in the trees as tho heavy wind 
were blowing thru them; then the 
rumbling past off to SW. 



Cloverdale ...... M.C. Balew.2.6 Many persons.... | Rumblings before the shock. 
Healdsburg.....- HaRe Ball se ser DAME: . sie ceisectss Attended by great rumbling noise, as 
thunder. 
Santa Rosa.....- Miss F. Locke... | R. Worthington... | Heard roaring. 
GO neemesee ss GO ween sere. Mr. Campbell.... | Heard a great roaring 2s. or 3 s. before 
the shock. 
Ose we isha eee QOgee: axe ox Watchman ...... Heard noise in SW.; then felt breeze; then 
felt shock. 
GO sen eee ete O27 sence Mrsmliloy dresses Heard noise; ran to window and opened 
it; then shock came. 
OO serietetse eats eleMi Sareea PAR TOVG eee eee ers Heard roaring and saw wave of earth 2 
y feet high. 
Cotati. Of Ly Jefireyxexe |: Samersoe ee ee Sound as of a strong wind before shock. 
TOMBS: seams Oss een sy AS DON. ss seer Heard roaring and said, ‘Oh, there’s 
thunder,’’ before the shock. 
(6 (65 eS rs GOs Saas es} Adfarmer’. seeseee Heard roar from SW. 
MOGs < cewek BOnt eis woe Mr, Scoudye. 2 -er Heard a great roaring sound from SE. 
Point Reyes Sta- GO seesi eters AU Taner pecs see Heard roar, then felt wind on my face. 
HON Sos. 2s 
Olemiar. fess see dO. eee A dairyman ..... Heard noise in the ground, got up, then 
felt shock. 
Bolinas! en eee Ky Haston.c so. = SAMs zo sue bee Rumbling noise preceded one after-shock 
on April 18. 
Calistoga. = -cc-- Dan Patten ....- ATE. =o Ss coe See A rushing noise before shock came. 
Napa ficteoee ton he Ell See Not named ...... A rumbling, then came shock. 
FALCULAS Beton octet GuBetowle 2.2. Somemenincamp | Heard low sound of earthquake, but did 
not feel shock. 
Redding 22-1 sis Li. FS Basset... - DIALOG oe eee iets ee Noise resembled a passing train; it pre- 
ceded and outlasted the shock. 
ChICO @)An-eeee nie E. Mayhew....-.. Same. 22s eeemee Rumbling sound thruout the disturbance 
like heavy-laden wagon passing house. 
Willows......... A. Ws Sehornwsc. PSamecresevtry ce Unusual rumbling sound preceded shock, 
gradually grew louder, and died away 
with the shaking. 
Colusa f.c2. aces Fred Roche..... Names. .ceee oes Sound like an approaching train coincided 
with shock. 
Berkeley........ Miss F. Locke... | Capt. ire Dept... | Was awakened by roar 5 s. before shock. 
San Francisco... | M. C. Erskine... | Same...........- Awake at 5" 10" a.m. Heard a great 
roaring from NE.; soon the shock came 
from same direction. 



