subterraneous convulsions, and "suddenly a prodigious column of boiling water is shot into the air with astonishing violence, and clouds of steam obscure the atmosphere. This is followed by successive jets, sometimes to the number of sixteen or eighteen in five minutes." The heights to which the jets rise are from ninety to 212 feet, the latter being the height of one measured by Lieutenant Ohlsen in 1804. These hot water springs appear evidently of volcanic origin, and whenever an earthquake shakes the island it is sure to be attended by the formation of fresh boiling springs. The waters of the great Geyser hold an immense quantity of flinty matter in solution, and where they overflow the basin, they deposit a stony crust upon the adjacent plants. The jets "are attended with a loud noise, and the ground trembles beneath the feet, whilst the velocity with which the jets and the accompanying steam are hurled into the air is astonishingly sublime. When stones are thrown into the pipe, they remain there until the succeeding jet projects them with great violence into the air, and they may be seen descending amid showers of boiling water."

Besides these very remarkable fountains, hot water springs have been discovered in various parts of the world, and amongst other places at St. Michael's in one of the Azores, where the water is of such an intense heat that it will boil an egg.

The boiling spring at Solfatara near Naples is another example, and many others might be mentioned; but in most cases the wonder is somewhat diminished by the circumstance of the spring being evidently connected with a volcano, and thus the hot springs in

P

England may be said to be the most wonderful in the world as there is no volcano near them.

In New Zealand, near the volcano of Tongariro, boiling springs burst out of the ground, which are thus described by Mr. Angas. "The crater of Tongariro is an immense truncated cone, giving vent, like an enormous safety-valve, to the steam and vapours that proceed from the boiling waters in its subterranean depths. Several other mountains are grouped with the stupendous peak of Tongariro, forming one grand mass or cluster; and the snow extends for a considerable distance down their sides. Near the termination of the snow there are boiling springs, which send up volumes of steam. Forests clothe the lower sides for some miles, and fern hills commence the ascent. It is only at intervals that any considerable quantity of steam issues from the crater. When I first saw the mountain from across the lake, there was no appearance of vapour, but after sunset it rose in continuous masses. The lake Roto-aira is upwards of 2,000 feet above the level of the sea, and there are numerous snow-fields and glaciers in the immediate neighbourhood" Nearly 100 boiling springs issue from the side of a steep mountain above Te Rapa. "They burst out, bubbling up from little orifices in the ground, which are not more than a few inches in diameter, and the steam rushes out in clouds with considerable force : the hill-side is covered with them, and a river of hot water runs down into the lake. The soil around is a red and white clay, strongly impregnated with sulphur and hydrogen gas: pyrites also occur. Several women were busy cooking baskets of potatoes over some of the smaller orifices; leaves

and fern were laid over the holes, upon which the food was placed: I tasted some of the potatoes and they were capitally done." "About two miles from this place," Mr. Angas continues, "on the edge of a great swampy flat, I met with a number of boiling ponds; some of them of very large dimensions. We forded a river flowing swiftly towards the lake, which is fed by the snows melting in the valleys of the Tongariro. In many places in the bed of this river, the water boils up from the subterranean springs beneath, suddenly changing the temperature of the stream, to the imminent risk of the individual who may be crossing. Along whole tracts of ground I heard the water boiling violently beneath the crust over which I was treading. It is very dangerous travelling, for if the crust should break, scalding to death must ensue. I am told that the Roturna natives, who build their houses over the hot springs in that district, for the sake of constant warmth at night, frequently meet with fatal accidents of this kind; it has happened that when a party have been dancing on the floor, the crust has given way, and the convivial assembly have been suddenly swallowed up in the boiling cauldron beneath. Some of the ponds are ninety feet in circumference, filled with transparent pale blue boiling water, sending up columns of steam. Channels of boiling water run along the ground in every direction, and the surface of this calcareous flat around the margin of the boiling ponds is covered with beautiful incrustations of lime and alum, in some parts forming flat saucer-like figures. Husks of maize, moss, and branches of vegetable substances were incrusted in the same manner. I also observed small deep holes, or wells, here and there amongst the grass

and rushes, from two inches to as many feet in diameter, filled with boiling mud, that rises up in large bubbles, as thick as hasty pudding: these mud pits send up a strong sulphureous smell. Although the ponds boiled violently, I noticed small flies walking swiftly, or rather running on their surface. The steam that rises from these boiling springs is visible at a distance of many miles, appearing like the jets from a number of steam engines."

At the distance of some miles from the volcanic mountain, lumps of pumice stone are seen floating down the river Waikato.

In addition to the hot springs may be mentioned those which appear to be constantly boiling, though, in fact, the water remains quite cold. Of this nature is the boiling spring at Peroul, near Montpelier, which is observed to heave, and apparently to boil up very furiously in small bubbles, but the water of which remains perfectly cool. What is called the mud lake of Java is another of these springs, but rising in a quagmire its bubbles are formed of mud, which, as they burst, throw up two or three tons of mud at a time, and immense volumes of dense white smoke.

CHAPTER V.

WATERFALLS AND WHIRLPOOLS.

WATERFALLS are of various kinds; and the most simple are when a series of sudden declivities occur in the bed of a river. These slight declivities, which are

frequent in the rivers of America, are called rapids; and as they generally give additional impetus to the stream, they are reckoned favourable situations for erecting mills. They also form only a slight impediment to navigation. A cataract, on the contrary, stops navigation, as it implies the fall of a whole river down a precipice, where, of course, a boat would be dashed to pieces. When the water falls from rock to rock in a succession of small cataracts it is called a cascade.

One of the noblest cataracts in the world is that at Niagara, in Upper Canada. It has been before mentioned that the five large lakes of Upper Canada are united so as to run one into the other, and in this manner Lake Erie is united to Lake Ontario, the lowest of the five, by the river Niagara. This river, which is extremely rapid, and 1650 feet in width, precipitates itself in its course over a rock, or rather precipice, 160 feet in perpendicular height. The whole river, in its course. from one lake to the other, is between thirty and forty miles in length; and about one mile above the falls its banks rise about a hundred feet from the water. At the grand falls the river is three-quarters of a mile broad, and the precipice curves nearly in a semicircle extending in the longest line on the American or eastern side. An island, called Goat Island, divides the cataract into two principal portions, viz. the American fall on the east, and the Horse-shoe fall on the west, or Canada side. A portion of the fall on the American side is cut off by a small island on the precipice; but the rest descends in one body, almost perpendicularly, from a height of 164 feet, and is 1000 feet in width. Both the falls on the American side are crossed by bridges. The Horse-shoe fall is fourteen