STATE GEOLOGIST. 185 
method of procedure, the size and shape of the house to be con- 
structed and the arrangement to be made for firing. 
The partitions and test walls were erected by the firm interested 
in the particular fire proofing submitted for test. 
The houses were all 914 by 14% by 12 feet high. The test walls were 
from 2 to 4 inches thick. The houses were built with a flue in each 
corner to provide for thorough circulation and quick heating. Grates 
were built 3 feet above the foundations and heavy protected doors were 
provided so that access was given for firing and observations. Ker- 
osene, pine and hard wood were used for fuel. The temperatures 
were to be kept from 1,700 degrees to 2,100 degrees, Fahrenheit, for 
one hour and then water from the city mains was to be thrown on to 
the heated walls for 214 minutes through fire nozzles with the regular city 
pressure. : 
The test that is of particular interest here was the one made 
upon the Sprickerhoff partition. This partition was built of concrete 
blocks 3 inches thick plastered one-half inch thick on both sides with 
King’s Windsor “browning mortar.” The blocks were composed of 1 
part Portland cement, 1 part sand, and 5 parts steam ashes—the blocks 
being laid in a cement mortar of I cement to 2 sand. The tempera- 
ture reached 1,868 degrees, Fahrenheit. Water was applied which 
stripped the plaster, but left the concrete portion unharmed and as. 
straight and plumb as before the test. 
There is nothing so convincing, however, as the actual test upon 
buildings in service. 
McMahon Cracker and Biscuit Company’s Building. —The build- 
ing of the McMahon Cracker Company, located in Chicago, burned on 
October 8, 1901. The entire structure was totally wrecked, except the 
portion holding five large bake ovens, each weighing 200 tons. These were 
situated from the third to the fifth floors and were supported by steel 
columns protected by a concrete shell composed of 1 part Louisville 
natural cement and 4 parts soft coal cinders, enclosed in a wire form 
plastered with cement mortar on the outside. The steel work in the 
other portion of the building was twisted and ruined and the walls, 
left unsupported, fell. But the heaviest portion of the building sup- 
ported by concrete protected steel remained standing. Figure 121 
shows the results of the fire. | 
The Borax Company’s Building.—The Pacific Coast Borax Com- 
pany’s building situated at Bayonne, N. J., was destroyed by fire, 
April 11, 1902. A large portion of the main building— the footings, 
walls, posts, girders, floors and a few partitions—were of steel con- 
crete. “The floors were concrete slabs 4 to 5 inches thick resting on 
and being monolithic with concrete beams, which were 4% inches 
