stars, or rather of suns (we must now use the more general word), to be added to those regarded by Daubrée as the bodies from which meteorites (and meteors of all classes, according to Professor Newton's just generalization) have proceeded. We may in one sense, indeed, be said to have multiplied Daubrée's sun-sources of meteors manifold, since for every sun now existing in space our views as extended show a whole family of sun-like orbs. But in reality we have only strengthened our theory by the addition of the suns which once belonged to our present sun's domain, for these alone could in any way explain the meteors and meteor-streams which had prevented us from accepting stellar (or rather extra-planetary) origin for meteoric bodies. It is to be observed, however, that these suns which we now introduce into the theory were not all active at the same time. We must regard them as distributed in time much as the stars are distributed in space—some very far off, others far off, indeed, but yet comparatively near; and in determining the distance of time at which they were active as suns, we can not range them in any definite order according to their mass. For instance, our own earth, though much more advanced in planetary life—that is, far cooler—than a giant planet like Jupiter, was probably in an actively sun-like state at a much more recent time: since the interval of time during which Jupiter has been cooling from the sun-like stage to his present fiery condition enormously exceeded, in all probability (owing to the vastness of his mass), the time occupied by the earth in passing from the sun-like stage through the fiery stage to her present cool and habitable condition; and, on the other hand, though Mars is much more advanced in planetary life than the earth, yet it is quite possible (though we can form no definite opinion in this case as in the former) that Mars might have been in the sun-like stage later than the earth.
We may observe here that we not only remove from Daubrée's theory, by this extension of it, the difficulties which had before prevented us from accepting it as a general theory of the origin of meteors, but we place the theories suggested by Tschermak, Meunier, Schiaparelli, and others, in a much more satisfactory light than before. It is properly objected to Tschermak's theory, by Professor Newton and others, that our earth can not be supposed to have ever had while a world explosive energy such as that theory imagines; but when the earth was in the sun-like state she could do all that might befit a sun. We know that our sun can eject matter from his interior with velocities sufficing to carry such matter forever away from him, for he has been caught, first by Professor Young in 1872, and several times since, in the act. What our sun with his much vaster energies can do ejectively to overcome the withdrawing power of his own much mightier mass, we may well believe that our earth in her sun-like days could do to overcome the attraction of her smaller mass. The only difference would be that while the sun on such occasions expels matter so as to
