"But, Doctor," interrupted Harry, "why should we stay here for a month?"
"Why, don't you understand," said the Doctor, "that we have discovered, right here on your mother's land, a coal mine that will certainly make her comfortable all her life and probably make you boys rich. We've got to find out enough about it to enable us to exploit it, and that will take a month at least."
"But tell us about the coal," said Jack.
The Doctor replied by singing:
"Old King Coal
Was a jolly old soul,
And a jolly old soul was he;
He called for his pipe and he called for his bowl,
And he called for his fiddlers three.
Every fiddler had a fine fiddle
And a very fine fiddle had he,
but," continued the Doctor, "not a man jack of them would tune up for Old King Coal till little Tom got back, because they had promised Tom not to set the fiddles going in his absence. That's a parable. It gives you fair warning that I'm going to keep my promise to our dearest comrade, Little Tom, and tell you nothing about this or any other coal till he comes back. But I tell you we shall have to stay here for a month at least, and that we need some sort of shelter against the heavy spring rains. So come, Jack, you are our architect. Tell us what sort of house to build."
Jack thought a few minutes, after which he said:
"We shan't need a house; at this time of year all we need is a shelter, closed in on three sides and open to the fire in front. We can build it of poles and cover it with a thatch of pine branches and other brush thick enough to shed the rain."
"But if we have only three sides to our house," said Jim, "how are we to keep the ends of the poles in place?"
"Oh, that's easy," said Jack. "We'll insert short bits of pole between them, with deep notches cut into them; and we needn't chink or daub at all. We ought to be able to build quite all the shelter we need, to-day and to-morrow, particularly as we are in a thick grove of young trees, just the size that we want for our poles. Get to work, every fellow of you, and cut poles with all your might."