The Great Geysir is farthest east of all the springs; it is indicated by a mound of sintery deposit like a heap of dry grey leaves, piled up about 30 feet above the soil, not quite regular in shape, as on the south, where the water flows away, the deposit spreads farther down the hill, and the rise is not so steep as on the north, where a miniature ravine causes the mound to be contracted and precipitous. At the summit is the basin, generally full to overflowing; it measures 56 feet by 46 feet, and is four feet deep, shelving gently to the bore, whose position is distinctly visible, even when the bowl is full, by the slight agitation of the surface immediately over it, and the darkness of the water. The deposit from Geysir and the other springs is formed with great rapidity. At every overflow it is stated to leave a layer of silex of the thickness of silver paper, and this is confirmed by the fact that I found near the stream flowing from Geysir a French newspaper completely coated, so that the printing was quite legible through a film of silex. I found also a bunch of moss Campion, every leaf and petal encrusted in a similar manner. Under a little fall which the Geysir water makes after it has become cool, and the deposit is less rapid, was hung a plover's wing; it was covered with a silicious film. The deposition of silex must be rapid indeed, if a newspaper, a tender flower, and a bird's feather, are overlaid before the hot water has had time to destroy them. The finest incrustations are not found in the rill from Geysir, but in the stream from the blue ponds, where leaves, flowers, and mosses are to be found in great abundance. It is interesting to notice the difference between deposits left by the same waters. The grey laminated sinter, of which the Geysir mound is built up, is different from the glossy white, orange, and scarlet deposit with which the stream bed from the blue ponds, the gullet of Strokr, and the fall of the Geysir rill, are lined. In the tiny ravine north of Geysir is a whistling steam jet and a few spluttering orifices. At right angles to this ravine is another gully leading up the hill, and serving in spring as a |