44 THE SAN FRANCISCO EARTHQUAKE AND FIRE. 
metal-covered sash and frames, with wire glass, and tin-covered 
sliding shutters. The earthquake racked the front sufficiently to 
prevent the shutters from working. The heat produced by the burn- 
ing insulated wire and other supplies was high and protracted. The 
reenforced-concrete beams of the roof were weakened by heat and 
will have to be replaced. The concrete in general, however, stood 
this trial exceedingly well in view of the protracted high tempera- 
ture. The fire caught through an unprotected rear door in the south- 
west corner, and the break in the roof made possible a very hot fire, 
which melted glass and even welded nails. The concrete floors and 
the column protection were not damaged in the slightest. If the 
methods of fire protection had been consistent throughout, it is prob- 
able that this building would have escaped without damage. 
POST-OFFICE BUILDING. 
The writer made a thorough examination of the post-office build- 
ing, on Mission street between Sixth and Seventh streets, in company 
with J. W. Roberts, superintendent of construction, of the Supervis- 
ing Architect's Office. This three-story structure rested on a founda- 
tion consisting of steel beams incased in concrete, carried through the 
soft alluvium to a hard gravel, the depth varying from 30 feet at 
Seventh and Mission streets to 12 and 14 feet at the opposite corner. 
The building had a steel frame, expanded-metal and concrete floors, 
and plastered expanded-metal suspended ceilings. All partitions or 
interior walls were of terra-cotta hollow tile, laid with full joints of 
Portland-cement mortar, the terra-cotta work being first class in every 
particular. The corridors were tiled and wainscoted with marble. 
The exterior walls were of granite and were thoroughly anchored, 
each stone being fastened to the steel work and doweled and pinned 
to the adjacent stones. The outer facing of granite is carried on the 
steel work and is not backed with brick, there being an inner wall of 
terra cotta, with a dead air space between, which serves as a passage- 
way for pipes, flues, etc. 
The ground at the corner of Seventh and Mission streets settled 
about 5 feet (PI. XLIII, B). The floor of the building Avas slightly 
cracked at that point, and Mr. Roberts stated that there was a set- 
tling of about If inches. The outer walls were considerably racked 
(Pis. XLIII, A; XLIV) by the earthquake, many stones having 
been shaken entirely loose from the steel work in some places, while 
in others a number of stones were started from their beds, and the 
anchorage was broken. There were also many cracks, especially in 
some of the exterior pilasters, which were formed of two steel col- 
umns, 12 feet apart, without diagonal bracing, the hollow space being 
used for heating and ventilating apparatus. These pilasters were 
badly racked. 
