"'Tis strange!" Dias said; "we have examined that spot more than once. There are great stones and boulders at the foot of the fall, and a large deep pool. Can a treasure be buried in that? If so, it will be hard indeed to get it."

Harry did not reply; his face was white with excitement. He walked forward slowly till he reached the edge of the pool. It was some fifteen yards across, and the colour of the water showed that it was very deep.

"I will dive, Harry," Bertie said; "I have gone down more than once in five fathoms of water to pick up an egg that has been thrown overboard." He stripped and swam out to the middle of the pool and dived. He was down about a minute, and on coming up swam to the shore. "I could find no bottom, Harry," he panted. "I am sure I must have gone down seven fathoms."

"Thank you, Bertie," Harry said quietly; "we will make up our minds that if it is there, we sha'n't get it at present. The foot of the valley is so flat that it would need a cut at least a mile long to let the water off, and we should therefore require either an army of men or a regular diving apparatus, which there would be no getting this side of England. However, it may not be there. Let us search now behind the fall."

There were some four or five feet clear between the sheet of water and the rock. At times, as Harry pointed out, there would be an even wider space, for the weather had been dry for the past two months, and the quantity of water coming down was but small, while in the wet season a mighty flood would shoot far out from the rock. The width of the stream in the wet season was shown by the broad bed of what was now but a rivulet. Looking upwards as they stood, the wall actually overhung them, and they could see the edge where the water poured over unbroken.

"There may be a cave here," Harry went on, "and it may be covered by these rocks piled up for the purpose. On the other hand, they may have fallen. I think that is the most likely explanation, for as the top projects beyond the bottom it is possible that some time or other there was a big fall."

They searched every foot of the rock within reach, but there were no signs of any man's handiwork. The rock was solid, thickly covered with dripping moss and ferns which had flourished in the mist and spray that rose from the foot of the fall. This they had ruthlessly scraped off with their picks. Silently they went out again at the end, and stood hopelessly looking at the fall. It was some time before Harry said, "We must move some of those stones now. Let us go at once and cut down some young trees, for we can do nothing with our hands alone, but must use levers. For that purpose we shall want straight wood, and strong. We had better get half a dozen, in case some of them break; make them about ten feet long, and from four to six inches thick, and sharpened slightly at the lower end."

In an hour the levers were ready.

"We had better breakfast before we begin, Dias. Your wife went off to prepare it when we came out from the waterfall. I dare say it is ready by this time."

In half an hour they were back again. They chose the central spot behind the fall, and then set to work. Some of the rocks were dislodged without much difficulty, but to move others, it was necessary to first get out the smaller ones, on which they rested. So they toiled on, stopping for half an hour in the middle of the day for food, and then renewing their work. By evening they had made an opening four or five feet wide at the top, and six feet deep, close to the wall. It was now getting dark, and all were fagged and weary with their work, the light was fading, and they were glad to return to camp. Maria came out to meet them. She asked no questions, but said cheerfully, "I have a good olla ready, I am sure you must want it."