Passing Lassen's meadows where the party lunched at a spring, indicated, as we approached, by a growth of willows, and striking upon the artemisia plain that constitutes the larger portion of the river valley, when about fifty miles from the station, we left the road by a blind trail, and approached the river, descending to the bottom land by a precipitous bluff thirty feet in height. The mountains approached close on the opposite side of the river, probably a mile distant, and enclosed us in a semi-circle, while the bluff was lined with a scattered growth of alders. It rained, was raining violently when we halted, and stretching a rope from alder to alder, with a blanket thrown over it, we thus made a tent, and established ourselves cosily to spend here the nation's Sabbath-day, the 4th of July. The rain turned into snow towards evening, and covered the mountains to their base, but melting as it fell where we were encamped, and with the cooing of the doves which filled the alders, the croaking of the frogs in the marsh next the river, and the patter of the rain upon the bushes, we had other music--nature's deep bass--in a constant roaring sound, like that of old ocean at full tide on a sand beach of the open coast of the Pacific; or like the sound of Niagara, heard half a mile away, but there was no discoverable cause. Going a mile up and down the river from the camp--if there is up and down to a dead river--we still heard the sound, the same in tone and power. Our Wyandotte--a member of the party who had crossed the plains with Col. Fremont--suggested that it was "the Humboldt sinking." All the day of the 4th of July we rested here, with our animals in clover, amid the snow which reached even to the foot of the mountains opposite, and the dirge played for us by the unseen hand. It was a quiet, still sweetly sad day--pleasant in memory, and such an one as we shall never spend again--so far from civilized humanity, and in a place so remote from human footsteps, it seemed a natural wonder which had never been properly examined and explained. Sooner than the old trappers anticipated, will the Humboldt be lined with farms, and the little mountain valleys filled with grazing herds, and the church spire and the cross upon an unassuming building in the centre of a six mile square prairie, indicate the advance of civilization. Yet, except in the mud-lake localities, there is no tract of country that can well be more unpromising than that about the Humboldt; and not many years will elapse before science will make plain and palpable that wonder of the world, "the sinking of the Humboldt." CHAPTER XIII.