Seeing, then, that we have not been able to find any cosmogony, or speculation, that gives us a more plausible idea of how the solar system has been formed, we shall try whether from the original nebula as imagined by Laplace, it is possible to separate the various members, and form the system in the manner described in his celebrated hypothesis. In other words, we shall endeavour to analyse the hypothesis. CHAPTER IV. PAGE 72 Preliminaries to analysis of the Nebular hypothesis. 73 Definition of the hypothesis. 75 Elements of solar system. Tables of dimensions and masses. 78 Explanation of tables and density of Saturn. 79 Volume, density and mass of Saturn's rings, general remarks about them, and satellites to be made from them. 79 Future of Saturn's rings. 80 Notions about Saturn's satellites and their masses. 81 Nature of rings seemingly not well understood. 81 Masses given to the satellites of Uranus and Neptune, Explanations of. 82 Volumes of the members of the solar system at density of water. PRELIMINARIES TO ANALYSIS OF THE NEBULAR HYPOTHESIS. It may be thought that there is little benefit to be derived from analysing an hypothesis which has been declared, by very eminent authorities in the matter treated of, to be erroneous in some points of very serious importance; but hypotheses are somewhat of the nature of inventions, and we know that it has often happened that many parties, aiming at the same invention, have altogether failed, while some other person using almost exactly the same means as his predecessors, has been entirely successful in his pursuit. How many times has it been pointed out to us, that if such a person had only gone one step further in the process he was following, or had only studied more deeply the matter he had in hand, he would have anticipated by many years one of the greatest discoveries of the age! In some cases the failure to take that one step was occasioned through want of knowledge acquired long years afterwards; whereas we think that in the case we have in hand, it can be shown that the want of knowledge acquired many years after he had formulated his hypothesis, or if otherwise, the want of faith in what he knew, enabled Laplace to construct an edifice which otherwise he could hardly have convinced himself could be built up in a practical form. We think also that if he had made the proper use of the knowledge he must have had of the law of attraction, he would have seen that no nebula could ever have existed such as the one he assumed, extending far beyond the orbit of the remotest planet. Furthermore, we think it can be shown that if he had thoroughly considered what must have been the interior construction of his nebula, he would have found one that would have suited his hypothesis in the main point, viz. condensation at the surface, at least equally as well as endowing it with excessive heat.