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Rh would "remain expanded about the nucleus in the shape of a very extended atmosphere; or it may be of an elastic nature, and be kept from uniting with the nucleus, as their elasticity causes the atmospheres of the planets to be expanded about them. In this case we have another property of the nebulous substance to add to the former qualities of its matter."

No one can read even an outline of these interesting speculations by an adventurer into the workshops of creation, without feeling awed by the boldness and sublimity of his views, as well as desirous of knowing what else he saw in his magic mirror, or thought he saw, of the machinery in motion. What he has told us of a mighty volume of nebulous matter is that "a nucleus, to which these nebulæ seem to approach, is an indication of consolidation," and that the faintness of the light in the parts outside the nucleus arises from "a gradual diminution of the length and density of the nebulous matter, occasioned by its gravitation towards the nucleus into which it probably subsides." He believes that "a pretty bright round nebula about a quarter or one minute in diameter, and looking no bigger than a pea, may have shrunk into itself till it is now nineteen hundred times more dense than at first,—a proportion of density more than double that of water to air." In another case he calculates that "the condensation may have reduced the nebulous matter to less than the one hundred and twenty-two thousandth part of its former bulk." To understand what these figures mean, suppose a sphere whose radius is nearly three thousand millions of miles, or as far as from the sun to our outermost known planet,