GENERAL EARTHQUAKE CONDITIONS AND EFFECTS. 27 
and the poor quality of the mortar used in the brickwork. Again, 
in the Hahnemann Medical College, on California street near Maple 
street, the destruction of the end walls was the result of bad design, 
the roof trusses butting against the walls and the floor timbers resting 
upon the walls without adequate tie. The poor quality of the mor- 
tar permitted a ready disintegration of the brick-veneered walls, 
although some band iron had been used for the purpose of strength- 
ening them. The Cathedral of St. Dominic, with its high, unbraced 
brick walls and its peculiar wood-sheathed spires, also proved a 
victim of poor design and workmanship ; the sheathing on the spires 
was shaken off and the collapse of the walls resulted in extensive 
damage to the interior. 
In interesting contradistinction to these failures was the Sailors 1 
Home, erected in 1858 for use as a marine hospital and condemned 
as unsafe after the earthquake of 1868. Its heavy brick walls, reen- 
forced with band iron and further stiffened by cross walls thoroughly 
bonded, are in excellent condition. The building rests upon rock 
and the framing is excellent; the rafters are fastened to a wall 
plate which ties the walls, causing the structure to move as a unit. 
The only cracks occurred where partition walls which had been added 
were shaken loose from the main walls and around the archways 
leading to the main stairway on the second and third floors, where 
no extra stiffening of the walls had been provided. The building in 
all other respects suffered no damage, there being no new cracks 
apparent in the exterior walls. 
The old red-tiled Spanish Mission Dolores (PL XXIII, B), built 
in 1777, with its adobe walls and wooden frame, was not injured, 
while its more modern successor was greatly damaged. The com- 
plete collapse of the tower of the new Mission Dolores was not 
brought about directly by the earthquake, but the damage was such 
that the tower had to be taken down, as shown in PI. XXIII, B. 
The group of buildings comprising the plant of the San Francisco 
Gas and Electric Light Company, built on the soft ground along 
San Francisco Bay just west of Fort Mason, was badly shaken, and 
none of the buildings escaped damage. The collapse of the stack 
wrecked the light slate-covered iron roof of the power house and 
started the fire that destroyed the roof of the boiler house. The 
ground settled very considerably under the vibrations of the earth- 
quake, and further destruction was caused by the unequal settling 
of the building. The main shock appeared to come from the north, 
and the north walls received the greatest damage. The end wall of 
the retort house was pushed out 1 foot at the center, but was saved 
from collapse by the tie-rods which held it to the roof truss. The 
walls were cracked at the northwest and northeast corners. The 
scrubber and gas-tar holder houses were wrecked, the heavy wooden 
