THE EFFECTS OF THE EARTHQUAKE AND FIRE 
ON BUILDINGS, ENGINEERING STRUCTURES, AND 
STRUCTURAL MATERIALS. 
By John Stephen Sewell. 
INTRODUCTION. 
SCOPE OF THE INVESTIGATION. 
The following pages contain the matter of a report dated July 5, 
190G, to Brig. Gen. Alexander Mackenzie, Chief of Engineers, United 
States Arnty, of an inspection made by me of the ruins of San 
Francisco, in accordance with Special Orders No. 97, dated War 
Department, Washington, April 23, 1906. 
I arrived in San Francisco on the morning of May 8, 1906, and 
remained until the night of May 19. My orders directed me to inves- 
tigate the effect of the fire and earthquake on buildings and engineer- 
ing structures in the territory affected by the earthquake, and author- 
ized me to visit such points in addition to San Francisco as it might 
be necessary to observe. As soon as possible after my arrival, I 
called on the various military and civil authorities, and procured 
from the latter permits authorizing me to enter and inspect the dam- 
aged structures. 
It appeared that in the territory affected by the earthquake, in 
addition to buildings of various types, there were the works of the 
Spring Valley Water Company and fortifications, light-houses, and 
railroad structures. Some rumors of collapsed tunnels on the coast 
division of the Southern Pacific Railroad had been circulated in the 
East before I left Washington. I found on inquiry, however, that 
no tunnels had collapsed, and whatever damage had been done, except 
to buildings along the line, had been wholly or partly repaired before 
I reached California. 
Inquiry among engineers and others competent to speak disclosed 
the fact that the dams of the Spring Valley Water Company were 
practically not injured by the earthquake. Considerable damage was 
done to some of their conduits and to the pipes of the distribution 
system. Inquiry in reference to these items disclosed the fact that a 
