When the burning city seemed doomed and the flames lit the sky farther and farther to the west, Admiral McCalla sent a trio of his most trusted men from Mare Island with orders to check the conflagration at any cost of property.  With them they brought a ton and a half of guncotton.  The terrific power of the explosive was equal to the maniac determination of the fire.  Captain MacBride was in charge of the squad, Chief Gunner Adamson placed the charges and the third gunner set them off.

Stationing themselves on Van Ness Avenue, which the conflagration was approaching with leaps and bounds from the burning business section of the city, they went systematically to work, and when they had ended a broad open space, occupied only by the dismantled ruins of buildings, remained of what had been a long row of handsome and costly residences, which, with all their treasures of furniture and articles of decoration, had been consigned to hideous ruin.

The thunderous detonations, to which the terrified city listened all that dreadful Friday night, meant much to those whose ears were deafened by them.  A million dollars’ worth of property, noble residences and worthless shacks alike, were blown to drifting dust, but that destruction broke the fire and sent the raging flames back over their own charred path.  The whole east side of Van Ness Avenue, from the Golden Gate to Greenwich, a distance of twenty-two blocks, or a mile and a half, was dynamited a block deep, though most of the structures as yet had stood untouched by spark or cinder.  Not one charge failed.  Not one building stood upon its foundation.

Unless some second malicious miracle of nature should reverse the direction of the west wind, by nine o’clock it was felt that the populous district to the west, blocked with fleeing refugees and unilluminated except by the disastrous glare on the water front, was safe.  Every pound of guncotton did its work, and though the ruins burned, it was but feebly.  From Golden Gate Avenue north the fire crossed the wide street in but one place.  That was at the Claus Spreckels place, on the corner of California Street.

There the flames were writhing up the walls before the dynamiters could reach the spot.  Yet they made their way to the foundations, carrying their explosives, despite the furnace-like heat.  The charge had to be placed so swiftly and the fuse lit in such a hurry that the explosion was not quite successful from the trained viewpoint of the gunners.  But though the walls still stood, it was only an empty victory for the fire, as bare brick and smoking ruins are poor food for flames.

Captain MacBride’s dynamiting squad had realized that a stand was hopeless except on Van Ness Avenue, their decision thus coinciding with that of the authorities.  They could have forced their explosives farther in the burning section, but not a pound of guncotton could be or was wasted.  The ruined blocks of the wide thoroughfare formed a trench through the clustered structures that the conflagration, wild as it was, could not leap.  Engines pumping brine through Fort Mason from the bay completed the little work that the guncotton had left, but for three days the haggard-eyed firemen guarded the flickering ruins.