30 THE SAN FRANCISCO EARTHQUAKE AND FIRE. 
the base was about 11 inches wide, with a half-inch horizontal 
crack leading from it along the reenforcement. The floor is in good 
condition, except the pavement, which broke into blocks, most of the 
planes of fracture coinciding with the actual joints between the dif- 
ferent sections. Under the circumstances — the undermining of the 
foundation by the slip as described — the structure developed remark- 
able strength. No brick or stone structure could have stood the shock 
so well. The rustic railing around the outside of the walk (PL 
XXII, B), which was of wrought-iron pipe covered with wire mesh 
and plastered with Portland-cement mortar, was distorted by the slip, 
but otherwise uninjured. 
At the bottom of Strawberry Hill is a bridge crossing over Stow 
Lake. This bridge is made of concrete, and showed no signs of 
cracking, although the banks of the lake slipped into the water. 
BEHAVIOR OF INDIVIDUAL STRUCTURES. 
GENERAL STATEMENT. 
The numerous fires that broke out all over the city were doubtless 
caused by the collapse of chimneys and the breaking of electric con- 
nections. These fires were at first confined to the territory south of 
Market street, and it is said that by 8 a. m. on the morning of April 
18 more than fifty fires were recorded. The early failure of the 
water mains rendered the city helpless and placed it at the mercy of 
the flames, the fury of which for three days threatened to complete 
one of the greatest disasters of recent years and to obliterate one of 
the most beautiful cities in the country. The conflagration was 
finally checked, at the barrier presented by a wide avenue, by a 
change in the direction of the wind and through the efforts of the 
fire department, using water pumped from the bay at the foot of 
Van Ness avenue. 
San Francisco consisted principally of frame and brick structures, 
with perhaps forty or more so-called " fireproofs," a few buildings 
of slow-burning construction, and the substantial Government build- 
ings. Many of the buildings contained mercantile stocks, and most 
of them were exposed to exterior fire conditions of maximum sever- 
ity. Since every type of construction was represented, the ruins 
afford a most excellent opportunity for comparative study, although 
the scope of the information obtained is incomplete, as a water test 
is lacking. 
In comparing the behavior of the various structures and structural 
materials it has been thought best to describe the condition in which 
certain individual buildings were left by the earthquake and fire, 
and to present the salient features of these buildings by illustrations 
with descriptive legends. The following descriptions, which for 
