witnessed this display? The roar of falling water filled the air to the exclusion of all voices and flowed in hissing cascades down the slope, into the ravine and across the meadow to the river. The sheep fled before the advancing column of steam and from a distance gazed with a foolish stare at a spectacle that they had often witnessed. Volume upon volume of steam, like the cauliflower-shaped clouds of active Vesuvius, belched into the air expanding under the reduced pressure and filled the air to the shutting out of the sun. Fountains of foam well over the brink. Explosion follows explosion and still that lofty tower of boiling water stands erect and masses of water fall to earth with a terrific crash. The column wavers, totters, falls. The eruption is over, the steam clouds lift and we rush up the dripping slope of geyserite, step over the rim into the hot basin and peer down into these depths whence came those rivers of water. The heat penetrates the thick soles of the riding boots but we walk to the edge of the tube and gaze down into the sizzling throat of the monster. A mass of foam is over the bottom, eighty feet below. It rises, we watch its ascent of the tube with the pace of a fly up a wall. It reaches the junction of the tube with the bottom of the basin and we photograph it, just a mass of foam with ascending steam. It wells over into the basin and we retreat. Soon the basin is full and overflows normally and the only evidence of the change that has taken place is the dripping cone and the steam rising from the brook as it rushes to cool itself in the icy river. [Illustration: _Bridge River, Brúará, near Geysir._ _The Tube of Geysir Filling, Photographed from within the rim of the Basin._] During the eruption I caught a glimpse of a dark object in the steam which fell with a thud upon the grass. After the display and the basin had filled I sought that spot and found a mass of geyserite twelve inches square and two inches thick. It was still hot. It is perforated with steam tubes in every direction. I stowed it in the packing case and it is now in the Science Museum at Springfield, Mass.