Our Essayist, however, is not exhausted by the efforts he has made in his destructive career. If he be a “proud setter down” of cosmological systems, he determines, in turn, to be a “putter up:” and so presents us with his own _Theory of the Solar System_; and an explanation of the mode in which all appearances in the Universe beyond may be reconciled with it. “It may serve” he says, “to confirm his argument, if he give a description of the system which shall continue and connect his views of the constitution and peculiarities as to physical circumstances of each of the planets. It will help us in our speculation, if we can regard the planets as not only a collection, but a scheme;—if we can give not an Enunciation only, but a Theory. Now, such a SCHEME, such a THEORY, appears to offer itself to us.”[121] The scope of this scheme, or theory, is, as we some time ago saw, to make our earth, in point of astronomical fact and reality, the largest Planetary Body in the solar system; its domestic hearth; the only part of the frame revolving round the Sun which has become a “WORLD.” We must, however, make short work of it. The planets exterior to Mars—especially Jupiter and Saturn—appear spheres of water, or aqueous vapour. The Earth has a considerable atmosphere of air and of vapour; while on Venus or Mercury—so close to the sun—we see nothing of a gaseous or aqueous atmosphere; they and Mars differing little in density from the earth. THE EARTH’S ORBIT, according to the Essayist’s theory, IS THE TEMPERATE ZONE OF THE SOLAR SYSTEM, where only the play of hot and cold, moist and dry, is possible. Water and gases, clouds and vapours, form, mainly, the planets in the outer part of the solar system; while masses, such as result from the fusion of the most solid materials, lie nearer the Sun, and are found principally within the orbit of Jupiter. After a further exposition of his “theory,” the Essayist observes that it agrees with the nebular hypothesis, SO FAR as it applies to the _Solar System_; exactly, and very sternly, repudiating that hypothesis as it applies to the Universe in general.[122] “If we allow ourselves,” says he, “to speculate _at all_ on physical grounds respecting the origin of the Earth, the hypothesis, that it has passed through a fluid and a gaseous condition, does not appear more extravagant than any other cosmogonical hypothesis: not even if we suppose that the other bodies of the Solar System have shared in the like changes. _But_, that all the stars and the nebulæ have gone, or are going through, a series of changes such as those by which the Solar System has been formed,—the nebular hypothesis, as it applies to the _Universe_ in general, is precisely the doctrine which I here reject, giving my reasons.”[123]