Mississippi was convulsed at the period of the earthquake which destroyed Caraccas, in 1812: South Carolina, at the same time, was also much convulsed.

Springs of inflammable vapour have been discovered in several parts of North America. The village of Fredonia, in the state of New York, is lighted by a natural discharge of gas, which is collected by means of a pipe into a gasometer.

Earthquakes are very frequent on the shores of the St. Lawrence, often of sufficient violence to split walls and throw down chimneys. Such effects were experienced in December, 1791, at St. Paul's Bay, about fifty miles from Quebec.

These convulsions and indications of subterranean heat appear, however, insignificant, in comparison with the stupendous volcanic forces we have been considering; nor can we regard them as a distinctly-marked continuation of the vast volcanic band. Whether future researches may disclose its prolongation in the more western parts of North America, is still matter of uncertainty, but traces of more decided volcanic action have been observed in this portion of the continent. Thus, near the source of the Missouri, amid the snow-clad summits of the Rocky Mountains, two peaks are said to occur, which emit smoke in considerable volumes, apparently from volcanos in a state of eruption. Boiling springs are also met with in the same vicinity. Traces of volcanic action have likewise been noticed in the Spanish River Mountains, and other parts lying between the Rocky Mountains and the Pacific; in which locality we also meet with the elevated volcanic cones of Mount Fairweather, fourteen thousand feet in height, and Mount St. Elias, sixteen thousand feet above the level of the sea. The two last-mentioned volcanos appear to be connected with the volcanic region of the Aleutian Isles, which, it will be remembered, form the northern commencement of the Asiatic volcanic region, and which thus appear to form a link, connecting the Old and New World,

CHAPTER XXIII.

OCEANICA.-AUSTRALIA.-NEW

ZEALAND.-POLYNESIA.

-POLYNESIAN VOLCANIC REGION.-CONCLUSION.

OCEA

Through hardy enterprise

Many great regions are discovered,

Which to late age were never mentioned.-SPENCER.

CEANICA, under which appellation may be included Australia, New Zealand, and the Polynesian Archipelago, forms another grand division of the globe.

The vast island of Australia, or New Holland, is about 2400 miles in length, and its width varies from 1200 to 1400 miles. This extensive tract of land does not appear to be traversed in its interior by any elevated mountain system; but, on the contrary, its principal mountain ranges border upon its shores, apparently encircling it on every side, and giving it, in this respect, some resemblance to Arabia and Persia. Finding that this region is possessed of this one natural feature in common with those territories, we shall be desirous of ascertaining whether any other similarity occurs; and upon inquiry we shall learn, that Australia, like Arabia and Persia, is remarkable for its deficiency of water; apparently not possessing any important river, and being, in some parts, subject to great droughts. The most characteristic feature of this region, however, seems to be the extensive lowland, which is supposed to occupy a very large portion of the interior.

The extreme south-eastern angle of Australia appears to enjoy a more agreeable climate than any other part of this vast island. Its greater distance from the equator gives it the advantage of a cooler temperature; to which the snowy mountains, called the Warragong Mountains, or Australian Alps, which are situated in this district, also contribute. Being likewise surrounded on three sides by the sea, it

possesses an insular climate, and abundant supplies of rain; and may be considered as one great basin, watered by the River Darling, River Murray, and their tributaries. Extensive downs occur, covered with excellent pasture; and some districts of so "fascinating a character," that Sir Thomas Mitchell has bestowed on the country to the south of the River Murray the appellation of "Australia Felix." The hills are generally of a conical form, and the rocks of which they are composed consist almost wholly of lava; a circumstance to which the greater fertility of this region may perhaps in part be attributed. Mount Napier, situated between Portland Bay and the Grampian Mountains, contains a crater. This mountain is surrounded for several miles by a rock of volcanic formation, and two extinct craters, named Mount Gambier and Mount Schanck, occur in the neighbouring districts of South Australia.

The Grampian Mountains may be considered as the commencement of a mountain system, which, running nearly parallel with the eastern coast of Australia, extends to Cape York and Endeavour Bay. The highest summit in this range is Mount William, 4,500 feet above the sea. In the parallel of Sydney, the range bears the name of the Blue Mountains. The mountains in this part do not appear to exceed three thousand feet in height, but, owing to the precipitous character of their surface, their more elevated parts are very difficult of access. The Liverpool range, which branches off to the westward, is of totally different character, the summits of this range consisting of rounded hills, or flat plains, covered with grass. The Hardwick range takes a northerly direction, and some of the loftiest summits in Australia appear to be situated in this part.

To the westward of this mountain system, a series of terraces occurs, which may be considered as the declivity of these mountains. These terraces consist of plains, of greater or less extent, separated from each other by low ridges; each ridge presenting a different geological formation. The terraces are destitute of timber trees, but are covered with luxuriant herbage, affording abundant food for cattle and sheep.

Beyond the terraces, the lowlands commence, the extent of which is yet unknown. These plains are in many parts extremely level, though in others they are slightly undulating; and they appear to have a general slope towards the south. In some districts they are wholly destitute of vegetation; whilst, in others, saline plants occur, without an intervening blade of grass. In Captain Sturt's harassing expedition into the interior, he passed over extensive plains spread out like a dark and gloomy ocean, the low ridges succeeding each other like waves of the sea, but covered with a wiry and matted grass; and in a distance of eighty miles, met with no other water than two putrid puddles. Some of these plains are covered with polygonum, a gloomy and leafless bramble; and in others, as far as the eye can reach, nothing is met with, except one kind of bush, forming a thick "scrub." The richest soils in this part scarcely produce anything better than a small number of stunted eucalyptus, or gum-trees, and cypresses; though a few highly-favoured spots are covered with good herbage, and trees of better growth.

The scenery in the Blue Mountains is of singular and striking character. These mountains consist principally of a succession of sharp ridges, intersected by remarkably abrupt and narrow ravines, or gullies, some of which are little less than 2000 feet in depth. Many of these ravines constitute the beds of rivers; and in some parts, numberless small cascades pour down the almost perpendicular sides. A chasm, or ravine, of this description, of great depth, but not more than 300 feet in width, forms the bed of the river Grose, a tributary of the Hawkesbury. Near one of the sources of that river occurs the cataract called Govatt's Leap; which, although the body of the water is inconsiderable, is remarkable for its great depth, and also for the character of the surrounding scenery. This cataract consists of a succession of cascades, the first of which is precipitated over a perpendicular rock, about 200 feet in height; and the entire fall to the bed of the river is estimated at full 1200 feet.

A remarkable burning mountain, called Mount Wingen, is situated on the eastern declivity of the Liverpool range. It was discovered to be in a state of incandescence in 1818, and