I have a vivid remembrance of my last night at the Upper Basin.  The hush of evening hallowed it.  Alone and undisturbed we looked upon a scene unequaled in the world.  Around us liquid columns rose and fell with ceaseless regularity.  The cooler air of evening made many shafts of vapor visible which in the glare of day had vanished unperceived.  So perfect were their images in the adjoining stream, that it was easy to believe the veil had been at last withdrawn, and that the hidden source of all this wonderful display had been revealed.  No sound from them was audible; no breeze disturbed their steadfast flight toward heaven; and in the deepening twilight, the slender, white-robed columns seemed like the ghosts of geysers, long since dead, revisiting the scenes of their activity.

[Illustration:  THE MORNING-GLORY POOL.]

[Illustration:  PRISMATIC LAKE.]

But geysers do not constitute the only marvels of these volcanic basins.  The beauty of their pools of boiling water is almost inconceivable to those who have not seen them.  No illustration can do them justice; for no photographer can adequately reproduce their clear, transparent depths, nor can an artist’s brush ever quite portray their peculiar coloring, due to the minerals held in solution, or else deposited upon their sides.  I can deliberately say, however, that some of the most exquisitely beautiful objects I have ever seen in any portion of the world are the superbly tinted caldrons of the Yellowstone.

Their hues are infinitely varied.  Many are blue, some green, some golden, and some wine-colored, in all gradations of tone; and could we soar aloft and take of them a bird’s-eye view, the glittering basin might seem to us a silver shield, studded with rubies, emeralds, turquoises, and sapphires.  Moreover, these miniature lakes are lined with exquisite ornamentation.  One sees in them, with absolute distinctness, a reproduction of the loveliest forms that he has ever found in floral or in vegetable life.  Gardens of mushrooms, banks of goldenrod, or clusters of asparagus, appear to be growing here, created by the Architect and colored by the Artist of these mineral springs.

[Illustration:  THE ROAD NEAR THE GOLDEN GATE.]

[Illustration:  THE EMERALD POOL.]

The most renowned of all these reservoirs of color is called the Emerald Pool.  Painters from this and other lands have tried repeatedly to depict this faithfully upon canvas, but, finally, have left it in despair.  In fact, its coloring is so intense, that as the bubbles, rising to its surface, lift from this bowl their rounded forms, and pause a second in the air before they break, they are still just as richly tinted as the flood beneath.  Accordingly this pool appeared to me like a colossal casket, filled with emeralds, which spirit hands from time to time drew gently upward from its jeweled depths.

[Illustration:  SUNLIGHT LAKE.]