We've come to find out our noisy friend, so let's get on.

Some day, when we've nothing to do, we may come here on a pleasure trip.

To-day we must work." "Stop a few minutes longer, father," said Mark, as the men went to another of the geysers a little lower down, one which had just thrown a column of water up some forty feet, and then subsided--a column not a third of the size of that which they had just seen.
"Very well," said the captain.

"Want to see it spout again ?" "I should like to, once," said Mark; and then, moved by that energetic spirit which is always inciting boys to do something, he ran to the other side of the basin, where a good-sized piece of rock lay half incrusted with the stony deposit of the hot spring.

It weighed about three-quarters of a hundredweight, but of so rounded a shape that it could be easily moved, and Mark rolled it over and over into the basin of the geyser while his father was pointing out something to the major across the little valley, and just as the stone was close to the rock-like opening the captain turned.
"I wouldn't do that, Mark," he said, as he realised his son's intention; but his warning came too late, for the final impetus had been given, and the stone disappeared in the hole.
Mark looked up apologetically as his father and the major came closer, and were listening to hear what would be the result, and expecting to note a tremendous hollow-sounding splash from far below.
What seemed to be a long time elapsed before there was any sign, and then with a roar up came the volley of water again so instantaneously that they had only just time to flee to the other side of the basin to avoid a drenching, possibly a scalding, while to the surprise of all there was a dull thud.