BEHAVIOR OF INDIVIDUAL STRUCTURES. 77 
XXV, .1, shows the corner of the building and the subsidence of 
the street at this point. The inlet at the corner indicates the original 
level of the street. There was a vault under the Market street side- 
walk, immediately behind the wall at the curb line. The basement 
floor in this vault was of concrete and had a total thickness of 7 or 8 
inches. The earthquake caused the earth to bulge up in the portion 
of the basement under the sidewalk, rupturing the concrete floor 
and turning it up on its edge, so that where there had previously 
been a clear headroom of 7^ feet the highest point of the bulge was 
within 3J feet of the beams carrying the sidewalk. The columns 
were of steel, protected with expanded metal and plaster. The 
girders were of steel and the space between them was spanned by 
reenforced-concrete construction. The reenforced-concrete beams 
were formed on the lower edge by a curved piece of flat steel (PI. 
XXIX, B). The concrete floor construction was damaged by the 
heat to such an extent that a heavy load of sheet iron on the third 
floor broke through, though it did not fall through bodily. The 
expanded metal that was used for reenforcing the slabs from rib to 
rib evidently got hot and w 7 as ruptured at this point. 
The cinder concrete used in the floor construction of this building 
was badly damaged by the heat, although the heat could not have 
,been very intense, as otherwise the ribs, with their exposed metal 
reenforcement, must have failed. Moreover, the girders did not have 
their lower flanges protected, yet they remained straight. A great 
many of the ribs, however, were deflected very considerably, but, 
owing to the fact that they were curved to begin with, this deflection, 
due to the fire damage, was not very apparent. The columns them- 
selves were practically uninjured, although the column covering was 
severely damaged and will probably have to be totally renewed. 
There were some terra-cotta partitions, terra-cotta furring, and furred 
ceilings in this building, all of which totally failed. The brick wall 
at the west side of the building exhibited some earthquake cracks, 
and at a number of places the brickwork spalled under the heat. 
The appraisers' warehouse was a very heavy structure, built on the 
old-fashioned monumental plan. (PI. XXVIII, A:) It was entirely 
of brickwork, w T ith some stone trimmings, and the exterior brick- 
work was laid with full header courses. It was practically undam- 
aged by the earthquake, the chimney even being left standing, and the 
fire did not get into it. It is probable that the shock at the site of 
this building w T as not so severe as it was at some other places, or the 
chimneys, at any rate, would have been thrown down. The building 
itself shows a very few slight cracks, which may have been due to 
