BEHAVIOR OF INDIVIDUAL STRUCTURES. 31 
convenience are arranged in alphabetical order, cover the structures 
not previously mentioned that were inspected by the writer, the 
total number embracing nearly every building that was left stand- 
ing in the burned district. The locations of these buildings can 
be found by reference to the map, PL LVI, and to the panorama, 
PI. LV. 
ACADEMY OF SCIENCES BUILDING. 
The Academy of Sciences building, 819 Market street, views of 
parts of which are shown in Pis. XXIV, A, and XXV, B, was of 
ordinary concrete construction and six stories high, and was com- 
pletely destroyed. 
A six-story annex having brick walls, concrete-filled cast-iron col- 
umns, and reenforced-concrete floors, was connected to the main 
building on the rear. The brick walls of the annex were badly 
cracked by the earthquake, and the building was subsequently com- 
pletely gutted by fire. The structure itself passed through a fairly 
hot fire successfully, although surrounded by buildings which were 
completely wrecked. Plaster of Paris was used on the concrete-filled 
cast-iron columns and seemed to stand fire much better than lime mor- 
tar. These columns are shown in PI. XXV, B, a view taken from 
the third floor looking southeast. An interesting feature of the 
building was the concrete-filled cast-iron column that supported the 
south wall. Owing to the unequal expansion of the cast iron and the 
concrete the cast iron failed, bulging from the heat and cracking on 
cooling, as shown in PI. XXIV, A. The j-inch or 1-inch thickness 
of concrete which covered the reenforcing bars proved insufficient in 
the basement, where the fire was fairly hot. The heat expanded the 
bars, thereby ripping oif the concrete layer and leaving the rods 
exposed. 
.ETNA (YOUNG, OR COMMISSARY) BUILDING. 
The five-story /Etna Building (Pis. XXIV, B; XXV, A; XXIX, 
Z?), on the southwest corner of Spear and Market streets, was occu- 
pied by the Sellers Brothers Hardware Company. It was built on 
piles and had self-supporting walls of gray granite, pressed brick, 
and terra cotta. The steel columns and girders were fireproofed with 
expanded metal, plastered. The expanded-metal reenforced-concrete 
floors rested upon steel girders with intermediate ribs of concrete 
supported by 5-inch by J-inch bands of steel without fireproofing 
which hooked onto the top flanges of the girders. 
One panel of the fifth floor, which was rather heavily loaded with 
tin plate, collapsed because of the expansion of the above-mentioned 
steel bands from the heat, which was sufficient to volatilize the tin 
even from the middle sheets of the pile. The fall of the load of tin 
