It was in vain. After the most desperate endeavors, this little group went to join the rest, the only fruit of victory being that Federal Street found itself the eastern barrier, the fire north of Summer Street having been checked at that point. Small triumph that! for the buildings west of Dewey Square were now thoroughly ablaze--and the South Station was in danger. In the open space known as Dewey Square, which is really nothing but the momentary widening of Atlantic Avenue at its intersection with Summer, the elevated railroad has its tracks. These, raised some twenty feet above the street, extend north and south along the western face of the South Station; there is a station at Essex Street, with stairways leading into the great depot itself. It was this elevated structure which now proved to be the compelling menace. Suddenly, in what manner it could not be said, there was seen to be a serpent of flame swiftly stealing along the Elevated's track. A tiny frill of fire, under a feathery cloud of smoke, ran down the wooden ties; sharp crackling sounds were heard; and a moment later the frame roof of the raised depot burst into light. One would hardly have thought that there was here sufficient fuel to jeopardize greatly the stout stone walls of the South Station itself; even to the firemen, skilled in such matters, risking their heads to drench those walls with water from a dozen lines of hose, the hazard, while grave, seemed far from hopeless. But this was not a day of reason nor of precedents. As the clock in the great facade showed five minutes before nine, the western eaves of the South Station caught. In this building, which is one of the busiest of the world's terminals, was little inflammable material save that which was movable. The structure was built almost entirely of brick and stone and steel. Much of the steel work, to be sure, was not so protected as to render it fireproof; yet in the building there would ordinarily have been scant fuel for an ordinary fire. But this was not an ordinary fire. Along the western side of the structure, where were baggage rooms, offices, and the like, this irreverent intruder found congenial occupation. In not more than twenty minutes this entire side of the Station was ablaze, and the flames had begun to eat their way upward to the vast iron roof of the train shed, which hung in a tremendous arch some eighty feet above the base of rail. Stretching north and south down the full length of this mighty shed stood at the summit of the arch a raised lantern, or texas. Supporting the weight of this roof, wide spans of steel branched, curving upward from the walls at east and west--and it was one of these walls whose integrity was now so bitterly beset.