Our progress through this tortuous waterway necessarily was slow; nevertheless, at the end of an hour and a half, the destroyer was stopped and we made ready for the final adventure.
It was decided that all fifteen of us should go, because less than that number could not carry our equipment up and down the steep mountainsides, and three or four men left to guard the ship would be utterly useless in the event of an attack.
So, with every nerve alert, we struck out through the trackless wilderness.
Three hours later we came upon six large steel conduits which we knew must convey the water power to the plant, and in a few minutes we had followed these to our goal.
Here we found ourselves upon the brow of a promontory directly behind and fully 300 feet above the Seuen-H’sin’s workshop. The promontory ended in a sheer precipice, from the outermost curve of which the conduits dropped straight down into the powerhouse. This tremendous fall of the six streams of water supplied the enormous energy to the turbines. The summit of this projecting ridge was fairly level, and for a distance of perhaps seventy-five yards at the end the timber had been entirely cleared away.
Extending out from the brow of the precipice, and resting upon the tops of the conduits where they plunged downward, was a narrow bridge of iron lattice-work which connected all six of the pipes and gave access to the bolts which tightened the steel elbows. Through holes in this grating, iron ladders fastened between the pipes and the granite cliff back of them descended clear to the bottom of the precipice.
A slight rail only three feet high protected the outer edge of this grid—a little hand-hold for the workmen in case of a misstep. From this dizzy balcony it would be possible to drop a stone almost upon the roof of the powerhouse.
After a quick look around, Ensign Hallock chose a spot a little back from the cliff to set up the mortars that were to throw explosives upon the building. He also prepared to place mines under the conduits. But first the machine guns were planted to command the surrounding timber, in case of an attack.
There still was no indication that the sorcerers suspected our presence in their vicinity; so, inasmuch as Hallock said his preparations would take some little time, Dr. Gresham determined to employ the interval in getting a closer look at the power plant.
One of the ladders down the precipice, he had noticed, was in such a position behind its water main that it could not be seen from the building; and he decided to attempt the approach by this means. To my delight, he made no objection to my accompanying him.