The lightning flashes were as vivid and rapid as ever, save that the glare may have seemed a trifle less blinding because of the flames, and there was no sign that the storm was decreasing. Suddenly, even while it appeared as if a small whirlwind enveloped a derrick that stood on the hill on the opposite side of the valley, another storm of fire descended from the sky, wrapping the heavy timbers in flames without shattering them, and flinging angry tongues of fire on nearly every timber in the towering pile.

For a few moments this lofty beacon burned as if trying to outshine the larger conflagration, and then, as the heat grew more intense, the small tank at its base became a receptacle for flames, which, overflowing, poured an angry stream of fire down the side of the mountain, igniting the various deposits of oil in its course.

In an incredibly short space of time, the valley, which had but a few moments before been deluged with water, was covered with flames and burning streams, which the rain appeared to feed rather than extinguish.

Then, as rapidly as they had come, the storm-clouds cleared away, the rain ceased, and the sun came out, clear and hot, but unable to send its rays through the impenetrable clouds of smoke which overhung the lowland, and wrapped the hills with a sable shroud.

Others besides Ralph and George had seen the first damage done by the lightning, for, living where such scenes were not infrequent, they feared, at each threatened storm, just that catastrophe which had occurred, and a small army of men were already on the scene by the time the two boys had recovered from the awe which had come upon them with this second danger that was pouring down upon the valley from the mountain-side.

It seemed a useless, because impossible, task to attempt to check the progress of or extinguish the burning oil, and yet the assembled multitude attacked it with a will that seemed all the more heroic because of the well-nigh hopelessness of the labor.

Fastening the now thoroughly frightened horses so that they could not release themselves from the shed, which was situated on ground sufficiently high to prevent the burning torrent from flowing around it, Ralph and George threw off their coats and vests, preparatory to doing what they could to check the course of this servant of man, now become master.

Quantities of shovels and pickaxes had been brought at the first alarm, and, armed with one of these, Ralph and George joined the others in throwing up embankments to check the course of the streams of burning oil, in order to hold them confined until the liquid should be consumed.

Then women and children were aiding in the work, for it was to save their homes from destruction that they labored, and foremost among them ever was George, struggling against the fire-fiend, as if everything the world held dear to him was in danger of destruction.

Then came the call for volunteers to get the cannon, which were nearly two miles away, that solid shot might be fired into the tank to open a passage for the oil not yet ignited, and Ralph was the first to offer his services.