"A moment's reflection," says Professor Tyndall, "will suggest that there must be a limit to the operations of the geyser. When the tube has reached such an altitude that the water in the depths below, owing to the increased pressure, cannot attain its boiling point, the eruptions of necessity cease. The spring, however, continues to deposit its silica, and often forms a _Laug_, or cistern. Some of these, in Iceland, are forty feet deep. Their beauty, according to Bunsen, is indescribable. Over the surface curls a light vapor; the water is of the purest azure, and tints with its lovely hue the fantastic incrustations on the cistern walls; while at the bottom is often seen the mouth of the once mighty geyser. There are in Iceland vast, but now extinct geyser operations. Mounds are observed whose shafts are filled with rubbish, the water having forced a passage underneath and retired to other scenes of action. We have, in fact, the geyser in its youth, manhood, old age, and death here presented to us. In its youth as a simple thermal spring; in its manhood, as an eruptive column; in its old age, as the tranquil _Laug_; while its death is recorded by the ruined shaft and mound, which testify the fact of its once active existence."
All that Professor Tyndall describes so eloquently of Iceland, exists in our Grand National Park in infinitely greater variety, and magnitude, and splendor. And much more: Iceland has no Gardiner's River. To find the nearest approach to the marvels of White Mountain Hot Spring, we must go to the opposite side of the globe--to New Zealand. In the celebrated Lake District of the North Island is a region of hot springs, far exceeding in extent and variety all the others in the world, save those of the Yellowstone. First of all, says Hochstetter, the most marvellous of the Rotomahana marvels is the Te Tarata--the Tattooed Rock--with its terraced marble steps projecting into the lake. The spring lies about eighty feet above the lake, on a fern-clad hill-slope, in a crater-like excavation, with steep reddish sides, from thirty to forty feet high, and open only toward the lake. The basin of the spring is about eighty feet long and sixty wide, filled to the brim with perfectly transparent water, which in its snow-white basin appears of a beautiful blue, like the blue turquoise. Immense clouds of steam curl up from the surface, obstructing the view, but the noise of boiling and seething is always audible. The water is slightly salt, but not unpleasant to the taste, chemically neutral, and possesses petrifying, or rather incrusting qualities, in a high degree. The deposit is silicious, like that of the Iceland springs and the springs around Yellowstone Lake, not calcareous, like those of Gardiner's River; yet the system of terraces built up by the deposit on the hill-slope has the same appearance of a cataract plunging over a series of natural shelves and suddenly turned to stone. The deposits cover an area of about three acres, a mere trifle compared with the square miles of similar formations on Gardiner's River and in the Yellowstone Basin.