The great cleft into which we were peering was about six feet wide at the bottom, coming together some twenty feet above our heads, having been apparently widened at the base by the action of the water, which, being here ankle-deep, rushed foaming over and around the many blocks of lava with which the channel was encumbered. As far as we could see, the fissure led straight away without a bend; and Joe was for trying to walk down it at once. I suggested, however, that we leave that for the present and try another plan.
“Look here, Joe,” said I. “If we try to do that we shall probably get pretty wet, and stand a good chance besides of hurting our feet among the rocks. Now, I propose that we go down to the ranch again, get our rubber boots, and at the same time bring back with us my father’s compass and the tape-measure and try to survey this water-course. By doing that, and then by following the same line on the surface, we may be able to decide whether it is really this stream which keeps ‘the forty rods’ so wet.”
“I don’t think there can be any doubt about that,” Joe replied; “but I think your plan is a good one, all the same, so let us do it.”
We did not waste much time in getting down to the ranch and back again, when, pulling on our rubber boots, we proceeded to make our survey. It was not an easy task.
With the ring at the end of the tape-measure hooked over my little finger, I took a candle in that hand and the compass in the other, and having ascertained that the course of the stream was due southeast, I told Joe to go ahead. My partner, therefore, with his arm slipped through the handle of the lantern and with a pole in his hand with which to test the depth of the stream, thereupon started down the passage, stepping from rock to rock when possible, and taking to the water when the rocks were too far apart, until, having reached the limit of the tape-measure, he made a mark upon the wall with a piece of white chalk.
This being done, I noted on a bit of paper the direction and the distance, when Joe advanced once more, I following as far as to the chalk-mark, when the operation was repeated.
In this manner we worked our way, slowly and carefully, down the passage, the direction of which varied only two or three degrees to one side or the other of southeast, until, having advanced a little more than a thousand feet, we found our further progress barred.
For some time it had appeared to us that the sound of splashing water was increasing in distinctness, though the stream itself made so much noise in that hollow passage that we could not be sure whether we were right or not. At length, however, having made his twentieth chalk-mark, indicating one thousand feet, Joe, waving his lantern for me to come on, advanced once more; but before I had come to his last mark, he stopped and shouted back to me that he could go no farther.
Wondering why not, I slowly waded forward, Joe himself winding up the tape-measure as I approached, until I found myself standing beside my companion, when I saw at once “why not.”
The stream here took a sudden dive down hill, falling about three feet into a large pool, the limits of which we could not discern—for we could see neither sides nor end—its surface unbroken, except in a few places where we could detect the ragged points of big lava-blocks projecting above the water, while here and there a rounded boulder showed its smooth and shining head.