Before starting the journey the Professor, as usual, uttered a few words of advice: "One of us must sit in the bow, one at the stern, and the other amidships. The one at the stern must propel the boat, as we cannot row through many of the places, and as the water is not deep, that will not be a difficult task. The ones at the bow and amidships should have the guns, and if there is no objection, I will take my place on the middle seat, where I can best take the observations on the way. The other places you should decide between yourselves."
"I am willing to take the bow, if Harry agrees." Harry sanctioned the arrangement, and when the lamps were securely fastened, Harry pushed the boat forward through the cavern. It did not take long to reach the slight turn which led to the large chamber, which was over one hundred feet long.
On the way to the chamber Harry had an opportunity to measure the depths of the water, and at intervals the Professor would call out for the depths, as he was making notes of the descent formed by the floor to the chamber. The oars gave a pretty fair idea, showing that the floor was only about five feet lower at the chamber than where the boat was launched.
Reaching the chamber Harry was directed to steer it to the right and skirt the wall going to the left, so that every part of it could be examined.
[Illustration: _Fig. 13 THE TREASURE CAVE_]
"I have another reason for this careful examination," remarked the Professor, as he was intently engaged in making notes on the board tablets. "It may be likely that the chamber has more than one outlet and if so, we must explore it also. Of course, I am most interested in the outlet to the south."
A circuit was made until they reached the outlet to the south, which Harry had discovered when the light on the ledge disappeared. The water throughout the cavern within the chamber was not over eight feet deep, and at the outlet to the south he could not touch bottom with the twelve-foot pole they carried. This outlet was contracted, and, judging from the width of the boat, could not be more than eight feet across, but it gradually widened, and the waters became shallower as they advanced.
George, who was in the bow, held up his hand as a warning. "Stop!" was all he said. All peered forward. The lights threw their beams forwardly through a broadening channel, beyond which appeared to be white forms ranged along the opposite wall.