Now, if I am to compare that which I have given as a theory of the earth, with the theories given by others under that denomination, I find so little similarity, in the things to be compared, that no other judgment could hence be formed, perhaps, than that they had little or no resemblance. I see certain treatises named Theories of the Earth; but, I find not any thing that entitles them to be considered as such, unless it be their endeavouring to explain certain appearances which are observed in the earth. That a proper theory of the earth should explain all those appearances is true; but, it does not hold, conversely, that the explanation of an appearance should constitute a theory of the earth. So far as the theory of the earth shall be considered as the philosophy or physical knowledge of this world, that is to say, a general view of the means by which the end or purpose is attained, nothing can be properly esteemed such a theory unless it lead, in some degree, to the forming of that general view of things. But now, let us see what we have to examine in that respect. We have, first, Burnet's Theory of the Earth. This surely cannot be considered in any other light than as a dream, formed upon the poetic fiction of a golden age, and that of iron which had succeeded it; at the same time, there are certain appearances in the earth which would, in a partial view of things, seem to justify that imagination. In Telliamed, again, we have a very ingenious theory, with regard to the production of the earth above the surface of the sea, and of the origin of those land animals which now inhabit that earth. This is a theory which has something in it like a regular system, such as we might expect to find in nature; but, it is only a physical romance, and cannot be considered in a serious view, although apparently better founded than most of that which has been wrote upon the subject.