On the summit of a cone twenty-five feet high was a boiling spring seven feet in diameter, surrounded with beautiful incrustations, on the slope of which we gathered twigs encased in a crust a quarter of an inch in thickness. On an incrusted hill opposite our camp are four craters from three to five feet in diameter, sending forth steam jets and water to the height of four or five feet. But the marvelous features of this wonderful basin are its spouting geysers, of which during our brief stay of twenty-two hours we have seen twelve in action. Six of these threw water to the height of from fifteen to twenty feet, but in the presence of others of immense dimensions they soon ceased to attract attention. Of the latter six, the one we saw in action on entering the basin ejected from a crevice of irregular form, and about four feet long by three wide, a column of water of corresponding magnitude to the height of one hundred feet. Around this crevice or mouth the sediment is piled in many capricious shapes, chiefly indented globules from six inches to two feet in diameter. Little hollows in the crust filled with water contained small white spheres of tufa, of the size of a nutmeg, formed as it seemed to me around some nuclei.[Z] We gave such names to those of the geysers which we saw in action as we think will best illustrate their peculiarities. The one I have just described General Washburn has named "Old Faithful," because of the regularity of its eruptions, the intervals between which being from sixty to sixty-five minutes, the column of water being thrown at each eruption to the height of from eighty to one hundred feet. The "Fan" has a distorted pipe from which are projected two radiating sheets of water to the height of sixty feet, resembling a feather fan. Forty feet from this geyser is a vent connected with it, two feet in diameter, which, during the eruption, expels with loud reports dense volumes of vapor to the height of fifty feet. [Illustration: OLD FAITHFUL. NAMED BY GENERAL WASHBURN.] The "Grotto," so named from the singularly winding apertures penetrating the sinter surrounding it, was at rest when we first discovered it. Externally it presented few indications of its character as a geyser. Private Williamson, one of our escort, crawled through an aperture and looked into the discharging orifice. When afterwards, he saw it belching forth a column of boiling water two feet in diameter to the height of sixty feet, and a scalding stream of two hundred square inches flowing from the cavern he had entered a short time before, he said that he felt like one who had narrowly escaped being summarily cooked.