A light laugh--instantly suppressed--at what was at first supposed to be the effect of the “overflowing hospitality” upon the speaker himself, went around the male circle until it suddenly appeared that half a dozen others had started to their feet at the same time, with white faces, and that one of the ladies had screamed. “What is it?” everybody was asking with interrogatory smiles. It was Judge Piper who replied:-- “A little shock of earthquake,” he said blandly; “a mere thrill! I think,” he added with a faint smile, “we may say that Nature herself has applauded our efforts in good old Californian fashion, and signified her assent. What are you saying, Fludder?” “I was thinking, sir,” said Fludder deferentially, in a lower voice, “that if anything was wrong in the reservoir, this shock, you know, might”-- He was interrupted by a faint crashing and crackling sound, and looking up, beheld a good-sized boulder, evidently detached from some greater height, strike the upland plateau at the left of the trail and bound into the fringe of forest beside it. A slight cloud of dust marked its course, and then lazily floated away in mid air. But it had been watched agitatedly, and it was evident that that singular loss of nervous balance which is apt to affect all those who go through the slightest earthquake experience was felt by all. But some sense of humor, however, remained. “Looks as if the water risks we took ain't goin' to cover earthquakes,” drawled Dick Frisney; “still that wasn't a bad shot, if we only knew what they were aiming at.” “Do be quiet,” said Virginia Piper, her cheeks pink with excitement. “Listen, can't you? What's that funny murmuring you hear now and then up there?” “It's only the snow-wind playin' with the pines on the summit. You girls won't allow anybody any fun but yourselves.” But here a scream from “Georgy,” who, assisted by Captain Fairfax, had mounted a camp-stool at the mouth of the valley, attracted everybody's attention. She was standing upright, with dilated eyes, staring at the top of the trail. “Look!” she said excitedly, “if the trail isn't moving!” Everybody faced in that direction. At the first glance it seemed indeed as if the trail was actually moving; wriggling and undulating its tortuous way down the mountain like a huge snake, only swollen to twice its usual size. But the second glance showed it to be no longer a trail but a channel of water, whose stream, lifted in a bore-like wall four or five feet high, was plunging down into the devoted valley.