But (2) what is the meaning of the division of the waters which are above the firmament from the waters which were under the firmament? At present all the water contained in the atmosphere, in the shape of vapour and clouds, is so insignificant in comparison with that vast volume of water which not only fills the ocean, but also permeates the solid earth, that such a notice of it seems unaccountable. Mr. Goodwin, indeed, maintains that there was an ancient belief, not only that the firmament was a solid vault, but that on it there rested another ocean, at least as copious as that with which we are acquainted. [Footnote: Essays and Reviews, p. 220] In support of this assertion he brings forward the phrase, "The windows of heaven were opened" (Gen, VII. 11) and other similar expressions. But such phrases as this evidently belong to the same class as the fanciful names so often given to the clouds in the hymns of the Rig Veda. Both expressions evidently point to a time when figurative language, if no longer a necessity, was at all events a common and favourite form of speech, and was understood by all. Dr. Whewell [Footnote: Plurality of Worlds, chap. x. Section 5.] has put forward the curious notion that when the creation of the interior planets was completed, there remained a superfluity of water, which was gathered up into the four exterior planets. But the only fact in favour of such an hypothesis is the close correspondence between the apparent density of these planets and that of water. Now, as will be seen immediately, there is strong reason to believe that the true density of these planets is much greater than their apparent diameters would seem to indicate; so that the one solitary ground on which the suggestion rests vanishes when it is examined. Apart from this, however, the suggestion that there would be any superfluous material when the work of creation was finished, is a very strange one. Neither of these views, then, can be accepted as giving a satisfactory meaning to the text. Astronomical investigations however, which have been carried on with great diligence during the last four winters, and which are still being continued with unremitting interest, have brought to light phenomena which seem to be in remarkable correspondence with the state of things spoken of in the text. It has already been noticed that the eight greater planets at present known to us are divided into two groups of four by the intervening belt of minor planets. These two groups have totally distinct characteristics. In density, magnitude, and length, of day the members of each group differ little from each other, while the two groups differ very widely. The moon is the only satellite as yet known in the inner group. The planets of the outer group are attended by at least seventeen satellites.