76 THE SAN FRANCISCO EARTHQUAKE AND FIRE. 
fectly solid. The shafts of the columns at about midstory height are 
therefore less efficiently braced than the portions on a level with the 
floors. Moreover, it is probable that the play in the connections of the 
steel work at the floor level would permit a little motion here with- 
out any damage, provided, in the meantime, the bracing at mid- 
story, due to the masonry, is sufficient to preserve the structure from 
collapse ; thus the connections would escape without material damage. 
As a matter of fact, some such action seems to have taken place. 
There was very little damage at the points where the steel work was 
fastened together ; at least, very little that was apparent. 
The failure of the masonry in the piers seems to have prevented 
the columns from being broken across in the middle or permanently 
deflected. It is an interesting speculation how near some of the 
unbraced steel-frame buildings were to total collapse under the 
stresses above described. In my judgment many of them were a 
little too near for safety. I saw a number of field bolts or rivets 
that I thought had probably been sheared by the earthquake, but as 
to most of them I was not sure that they had ever been in place. In 
one or two instances, however, the earthquake effect was indisputable. 
As it is very difficult to discuss the earthquake effect in a general 
way, however, it will be taken up further in connection with the sub- 
joined detailed description of the effect of the earthquake and fire 
on individual buildings in San Francisco. 
BEHAVIOR OF INDIVIDUAL STRUCTURES. 
ACADEMY OF SCIENCES BUILDING. 
The Academy of Sciences building, on Market street, was interest- 
ing because of its interior construction. This building had cast- 
iron concrete-filled columns and Ransome reenforced-concrete floor 
construction. So far as it was possible to ascertain, no damage was 
done to the reenforced concrete or to the columns by the earthquake. 
The building was gutted and the floors considerably damaged by the 
fire, but the columns were not damaged, and on the whole the build- 
ing stood very well. A very good view of this building was given 
in the Engineering News of June 7, 1906, page G23. (See Pis. XXIV, 
A; XXV, B.) 
.ETNA (YOUNG, OR COMMISSARY ) BUILDING. 
The steel-frame structure at the corner of Spear and Market 
streets, locally known as the " commissary building, 7 ' because it was 
said to have been erected originally with a view to furnishing offices 
for the Commissary Department of the Army, rests upon piles, 
and suffered relatively small damage from the earthquake. PI. 
