Not long before they reached the stopping place, dark clouds had begun to rise over the mountains to the west, and gradually the whole western sky became overcast.
"Looks like we were going to have a rain storm," said Hugh; "and I wish we might, and a good hard one. It would put out the fire on the mountains and cleanse the air of the smoke."
"Yes," replied Jack, "I wish it would rain. I hate to see all that timber burning. It will take a long time for the mountains to become green again."
"Yes," said Hugh, "many and many a year; and sometimes, of course, after the fire has gone over the hills like that they never again are covered with timber. I have seen mountains way down in the south-west that at one time must have been covered with splendid great trees, and then had been burned over and no trees ever grew there again. There are big logs lying on the hillside now that are all that is left of those old forests, but no sign of any new timber springing up anywhere."
"Well, how long ago were those mountains burned over?" asked Jack.
"You can't prove it by me," said Hugh. "I've asked that question a good many times, and I have never found anybody that was old enough to know anything about when the fires took place. It must have been long, long ago."
"But why don't those old logs that you were speaking about, rot and disappear?" asked Jack.
"I'll tell you why," said Hugh. "It's because that country is so dry. I don't believe more than six inches of rain falls there in the year, and nothing ever rots; things just dry up and lie there, getting drier and drier all the time."
"And yet," said Jack, "when we came down through the mountains from the north, we saw lots of country that had been burned, and almost everywhere a lot of new green timber was springing up to take the place of the old burnt tree trunks that were getting ready to fall."
"That's so," replied Hugh; "but I remember that we passed over some places where the forests had been burned, where there was no sign at all of anything growing, no sign of any soil; nothing except the bare gravel or the rock."