Mr. Oxley, on the Lachlan, was only 500, there being a still greater fall of country beyond these two points. The maximum height of the fossil bank was 300 feet; and if we suppose a line to be drawn from its top to the eastward, that line would pass over the marshes of the two rivers, and would cut them at a point below which they both gradually diminish. Hence I am brought to conclude that in former times the sea washed the western base of the dividing ranges, at or near the two points whose respective elevations I have given; and that when the mass of land now lying waste and unproductive, became exposed, the rivers, which until then had pursued a regular course to the ocean, having no channel beyond their original termination, overflowed the almost level country into which they now fall; or, filling some extensive concavity, have contributed, by successive depositions, to the formation of those marshes of which so much has been said. I regret extremely, that my defective vision prevents me giving a slight sketch to elucidate whet I fear I have, in words, perhaps, failed in making sufficiently intelligible.
Now, as we know not by what means the changes that have taken place on the earth's surface have been effected, and can only reason on them from analogy, it is to be feared we shall never arrive at any clear demonstration of the truth of our surmises with regard to geographical changes, whether extensive or local, since the causes which produced them will necessarily have ceased to operate. We cannot refer to the dates when they took place, as we may do
in regard to the eruptions of a volcano, or the appearance or disappearance of an island. Such events are of minor importance. Those mighty changes to which I would be understood to allude, can hardly be laid to the account of chemical agency. We can easily comprehend how subterranean fires will occasionally burst forth, and can thus satisfactorily account for earthquake or volcano; but it is not to any clashing of properties, or to any visible causes, that the changes of which I speak can be attributed. They appear rather as the consequences of direct agency, of an invisible power, not as the occasional and fretful workings of nature herself. The marks of that awful catastrophe which so nearly extinguished the human race, are every day becoming more and more visible as geological research proceeds. Thus, in the limestone caves at Wellington Valley, the remains of fossils and exuviae, show that their depths were penetrated by the same searching element that poured into the caverns of Kirkdale and other places. They are as gleams of sunshine falling upon the pages of that sublime and splendid volume, in which the history of the deluge is alone to be found; as if the Almighty intended that His word should stand single and unsupported before mankind: and when we consider that such corroborative testimonies of his wrath, as those I have noticed, were in all probability wholly unknown to those who wrote that sacred book, the discovery of the remains of a past world, must strike those under whose knowledge it may fall with the truth of that awful event, which language has vainly endeavoured to describe and painters to represent.
Illustration 12
