But it was slow work, for every now and then the sand from above crumbled down, great pats dropped from amongst the roots as soon as that beneath was taken away, and at the end of half-an-hour a feeling of despair accompanied the deadly weariness that now attacked his arms and shoulders, and involuntarily Tom Blount uttered a piteous cry.

It was from the hopelessness of what he was doing that this cry escaped him, but the dog took it for one of encouragement, and it plunged its nose into the loose sand again, grew more and more excited as it tore away, and suddenly, to Tom’s astonishment, head and shoulders disappeared, and it gradually struggled on till even the long thin tail disappeared.

Reaching down, the boy now found the sand come away more easily, and he was thrusting his arm in as far as it would go, when he felt the dog’s cold nose against his hand; the dry sand seemed to boil up as he snatched back his arm, and directly after the dog worked itself out again, to stand barking with all its might, and then begin scratching once more.

After working a few minutes longer, Tom reached in again, and found that his hand moved about freely in one direction, but touched pieces of root in the other, and then he started back with a cry of horror, for down in a hollow between two pieces of root he felt a face.

The fear was only momentary. Then he was searching again, and this time easily touched the face, which was quite clear of sand, the roots above striding over it, so to speak, and, as he felt upward, proving to be some inches distant.

But the face was cold and still, and despair crept over the worker again. He fought it back though, tore away at the sand, and at the end of a few minutes had cleared an opening like a rabbit burrow, which he could see led right to the roots and must convey air.

Then with a tremendous burst of barking the dog made a plunge to get in, half filling the burrow before Tom could hold it back, when the intelligent beast stood with its tongue out, panting heavily, and seeming to question him with its eyes.

Tom thought for a moment, then he took off his neckerchief, pulled out his pocket-book, and tore out a leaf of paper, one side of which was covered with the names of the moon’s craters.

“Come away,” he cried to the dog, as he carefully stepped out on to the firm ground, the dog barking excitedly, but following him.

“Must stop and keep the hole open,” thought Tom; and then, laying his paper on a tree-trunk, he wrote clearly:—