This form of protection is equally imperative in the brick. stone and concrete districts of all large cities where great values are housed in close proximity. . . . We must come eventually to the equipment of all commercial, factory and office buildings with metal window frames and wire glass. . . . Fires will then be unit fires, extinguished easily by a competent fire department within the buildings in which they originate; for the protection of window openings not only prevents fire from entering, but prevents fire from issuing out of the burning building. . . Having thus fortified city buildings one against the other, extensive fires within individual structures can be prevented by the use of the now well established automatic sprinkler system, The automatic sprinkler applies the water without the help of human agencies while the fire is still incipient. It will operate in a dense smoke as well as in a clear atmosphere. It will not throw excessive deluges of water in wrong places as the fire departments are continually forced to do. With our window openings protected and our buildings equipped with such extinguishers, the conflagration hazard in mercantile districts will be eliminated. There will then remain for consideration our immense residence districts constructed almost wholly of wood surrounding the mercantile centres, like fagots around a funeral pyre. We can lessen the loss here by the abolition of the use of wooden shingles.
Experience justifies the increasing reliance placed upon automatic devices for extinguish ing fires in their incipiency, and here the auto matic sprinkler stands supreme. Briefly de
scribed, this system consists of an elaborate ar rangement of pipes regularly spaced under the ceilings for all portions of the building and supplied with water from elevated tanks, pumps or city connections. At regular intervals (for about every 75 or 80 square feet of floor area there are so-called "sprinkler heads" which are so arranged as to open whenever a sufficient rise in temperature will soften the fusible metal with which the joints have been soldered. To meet the nature of the risk protected, the solder may he adjusted to fuse at any ar ranged temperature, usually from 165 to 360 de grees. When once started the flow of water will continue, and to avoid unnecessary water damage after the extinguishment of the fire it is necessary to have the system supplemented with some automatic fire alarm device con nected with the city's fire department or some other central station.
The manifest advantage of such an auto matic system lies in the fact that it is always on duty, and as has been well said, "applies the right amount of water in the right place at the right time," and does this without the in tervention of human help. The efficiency of the plan is indicated by the fact that fully 95 l" American Fire Waste and Its Prevention," Annals of the Americas Academy of Political and Social Science, March 1917, pp. 163-171.