BEHAVIOR OF INDIVIDUAL STRUCTURES. 109 
It will be noted that there was no reenforcecl-concrete construction, 
pure and simple, in San Francisco. The warehouse of the Bekins 
Van and Storage Company (PI. XXVII, A), in process of construc- 
tion, had reenforced-concrete columns and floor construction and 
brick Avails. The Avails Avere badly damaged by the earthquake, but 
the reenforced concrete Avas absolutely uninjured. This building, 
however, Avas unfinished, and the loAver portion of it was not sub- 
jected to the stresses which Avould have resulted had it been com- 
plete, with all its contents. In that case the energy due to the 
vibration of the greater superincumbent mass might have produced 
effects which were not produced in its unfinished condition. 
One-half of the circular observatory on Strawberry Hill, in Golden 
Gate Park (PL XXIII, .4), Avas throAvn doAvn by the earthquake. 
I did not make a personal examination of it, except from a distance, 
but Avas informed that it had been reenforced Avith heavy iron rods 
bedded in the masonry. It Avas reported to me that these rods Avere 
broken at the point Avhere the collapsed portion had separated from 
the part still standing. The general effect of the earthquake on 
hollow circular structures of all sorts seems to have been a tendency 
to increase their diameter. Where this tendency Avas very marked, 
it naturally caused their collapse. 
Practically all the other photographs submitted and not spe- 
cifically referred to in the foregoing pages Avere taken Avith a A 7 iew 
of shoAving earthquake damage. The toAver of the church next to 
the old Mission Dolores Avas dangerously near being thrown down, 
and had to be pulled down later, as sIioavii in PI. XXIII, B. PI. 
XXXVII, B, is a vieAV of a brewery Avhich had been four stories 
high, Avith a tower at the corner extending to a considerably greater 
height than the building. The damage Avas due to earthquake alone. 
PL XXI, .4, sIioavs a case of earthquake damage pure and simple. 
It will be observed that the face bricks Avere not bonded, and were 
thrown down in large quantities. None of the brickwork in this 
building seems to have been of a very good quality. 
An old-fashioned brick building of ordinary construction near 
Fort Mason appeared to have survived (he earthquake absolutely 
undamaged. This example indicates the variation in the intensity 
of the earthquake within relatively short distances. 
PL XXXIII, .1, sIioavs a building, known as the Butler Building, 
which Avas partially completed at the time of the earthquake. When 
I first saw it the side Avail, which appears in the illustration as 
nearly torn down, was standing at about the same height as the front 
wall (shown at the right side of the picture). This side Avail had a 
feAV earthquake cracks in it which were plainly visible, but it was 
a matter of surprise to see, a few days later, that the wall had been 
practically torn doAvn; for if this Avail Avas damaged sufficiently to 
