They were about to advance and look down again, but there was a roar, and the water rushed to the surface just high enough to fill the basin, and for a portion to run gurgling over where the rim, which seemed to be formed of a curious deposit, was broken away, and trickle down toward the valley.
“I say, aren’t it hot?” said Billy Widgeon, who had thrust in his hands before the water ran back. “Why, you might cook in it. I say, bo’sun, look ye here; why if it aren’t just like the stuff as my old mother used to scrape out of the tea-kettle at home.”
Small stooped and broke off a scrap of the deposit, and examined it, holding it out afterwards to Mark.
“Yes,” said the major, who examined it in turn, after Mark had taken it to him, “the man is quite right. It is a limy deposit from the boiling water, similar to what is found in kettles and boilers. Shows that the water is very hard, eh, captain?”
“Yes, I suppose that’s it,” replied Captain Strong. “But all this is very interesting for travellers, and does not concern us. 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.