ISOSEISMALS: DISTRIBUTION OF APPARENT INTENSITY. 203 
(Charles Kobes.) — The vibrations in Santa Rosa were at first north and south, then 
east and west, and finally vertical. Mr. Kobes relates an instance in regard to the earth- 
quake which occurred about 8 years ago. At that time sulfur fumes came up from under 
his house which almost drove his family from home. On April 16, two days before the 
shock, sulfur fumes came up equally as strong, and he told his family that he believed it 
meant another earthquake. 
(Mr. Miller.) — The vibrations in Santa Rosa were at first north and south, then east 
and west, and finally vertical. 
VICINITY OF SANTA ROSA. 
(Drury Butler.)—-Near the top of Taylor Hill, in a marshy place, there was a landslide, 
the earth having slid on a clayey bottom. In Bennett Valley the country is hilly, with 
some underlying basaltic formation, and very little damage was done. Beyond a dis- 
tance of about 3 miles from Santa Rosa, only an occasional chimney was found that 
had been injured, and the effect was much less as higher ground was reached. Along the 
Sonoma road to the Rincon district school, beyond 2 miles from Santa Rosa, the damage 
was very slight. The road follows the creek, but here the hills come down to the creek. 
Over half the chimneys were uninjured, and none were completely thrown down except 
right along the creek. No bottles nor glasses were thrown from the bar-room shelves. 
Along the creek the shock was more severe than back from it. In the vicinity of the 
Sonoma County Hospital, the soil is very like the Santa Rosa soil and the shock was felt 
more. Glasses and bottles were thrown from the shelves in the bar-rooms, and at the 
hospital a marshy place along the creek slipt toward the creek and the flow of springs was 
greatly increased. The hospital also was pretty badly damaged. A trip was made out 
on the Petaluma road to the Copeland district school, then to Cotate, to the Durham 
district school, and back to Santa Rosa. The road followed the base of the hills for 
about 7 miles, then turned into the valley and was on the valley floor the remainder of 
the way. On the hillside very little damage was done, even to chimneys, while in the 
valley the chimneys were as a rule thrown down. I could hear of no cracks in the 
ground in the valley; and in only one place, about 2 miles from Santa Rosa, on 
the Petaluma road, could I hear of any increase or change in the flow of springs. 
From these observations it was apparent that lines of equal intensity would follow the 
contour and geological lines of the country, and that the character of the soil on which a 
building stood determined the effect upon it, or the apparent intensity of the shock. 
The general motion of the waves of the earthquake, as reported to me, was from north 
to south. 
Cotate (C. L. Jeffrey). — At Cotate, 9 or 10 miles south of Santa Rosa, on the open 
level floor of the valley, the surface of the earth waved like water; objects were thrown 
southeast; hanging objects swung northeast and southwest. Only one maximum was 
observed. ‘Trees swayed heavily, and there was a sound as if a strong wind were coming 
before the earthquake began. 
Wells East of Santa Rosa (i. 8. Larsen), — At the city pumping station, 1.5 miles east 
of Santa Rosa, there are 4 wells dug 50 feet and connected with a tunnel 450 feet long. 
Within each well there is a bored well 8 inches in diameter and 108 feet deeper than the 
dug well. The water began to rise immediately after the shock, and has risen, May 8, 
1906, 15 feet higher than it was before, altho the pumps have been run to their full 
capacity. The water tastes more of sulfur since the shock. The shock caused the pipes 
and boiler to leak. 
At Peters’ ranch the warm spring was little affected. Mr. Peters, the younger, says 
that for a day or so after the shock the water in the spring. was lower, but that it is now 
normal, 
