78 THE SAN FRANCISCO EARTHQUAKE AND FIRE. 
ordinary settling and not at all to earthquake. Mr. Roberts, the local 
representative of the Supervising Architect's Office, informed me that 
during the construction of the building there had been some unequal 
settling, so that one end was about 1J inches lower than the other, 
but that this settling had been at a uniform rate from one end to the 
other, so that it had caused practically no damage. On the interior 
there were many solid brick partitions, with some unprotected cast- 
iron columns. The floor construction was of steel or iron beams 
and segmental brick arches with a span of 3 to 6 feet. 
It is worthy of note that immediately after the earthquake and 
fire three of the very few buildings in the burned district which were 
absolutely open and ready for business in every particular were the 
post-office, the mint, and the appraisers' warehouse. The massive 
construction used in these Government buildings would appear to 
have been a very good investment. 
ARONSON BUILDING. 
The ordinary ten-story steel-frame structure at the corner of Third 
and Mission streets known as the Aronson Building had terra-cotta 
column coverings and partitions and cinder-concrete floors, all of 
which were of the types described in this paper as common in com- 
mercial buildings. The building seems to have been occupied for 
light commercial purposes, and the fire test to which it was subjected 
was therefore somewhat more severe than that prevailing in office 
buildings. 
A column in the basement was buckled, and two of the columns on 
the first floor were badly buckled near the ceiling, as shown in PI. 
XXVII, B. These results, so far as the condition of the fireproofing 
is concerned, are typical not only of the other stories of the Aronson 
Building, but of similar work in other buildings throughout the 
burned district. Some of the work in the Aronson Building was not 
severely tested by the fire and was still intact. An examination of it 
shows that it was as well done as similar work in any other commer- 
cial building in San Francisco. Where the fire was not very hot this 
kind of fireproofing protected the steel and suffered not more than 10 
or 15 per cent of damage itself; where the fire reached the average 
temperature the fireproofing suffered a loss of 50 to 100 per cent, and 
where the fire was a little hotter than the average the total loss of the 
fireproofing and serious damage to the steel work was not at all 
uncommon. Damage to fireproofing such as that here described 
occurred in the James Flood Building, the Emporium Building, the 
building of the Spring Valley Water Company, the Mills Building, 
and every other building in which hollow tiles were used. 
The buckled column in the basement was about the worst example 
of this sort of damage that I discovered, although I am inclined to 
