The space, therefore, in the air, or in the immensity of space, that our solar system takes up for the several worlds to perform their revolutions in round the Sun, is of the extent in a strait line of the whole diameter of the orbit or circle in which Saturn moves round the Sun, which being double his distance from the Sun, is fifteen hundred and twenty-six million miles; and its circular extent is nearly five thousand million; and its globical content is almost three thousand five hundred million times three thousand five hundred million square miles. [NOTE by Paine: If it should be asked, how can man know these things? I have one plain answer to give, which is, that man knows how to calculate an eclipse, and also how to calculate to a minute of time when the planet Venus, in making her revolutions round the Sun, will come in a strait line between our earth and the Sun, and will appear to us about the size of a large pea passing across the face of the Sun. This happens but twice in about a hundred years, at the distance of about eight years from each other, and has happened twice in our time, both of which were foreknown by calculation. It can also be known when they will happen again for a thousand years to come, or to any other portion of time. As therefore, man could not be able to do these things if he did not understand the solar system, and the manner in which the revolutions of the several planets or worlds are performed, the fact of calculating an eclipse, or a transit of Venus, is a proof in point that the knowledge exists; and as to a few thousand, or even a few million miles, more or less, it makes scarcely any sensible difference in such immense distances.—Author.] But this, immense as it is, is only one system of worlds. Beyond this, at a vast distance into space, far beyond all power of calculation, are the stars called the fixed stars. They are called fixed, because they have no revolutionary motion, as the six worlds or planets have that I have been describing. Those fixed stars continue always at the same distance from each other, and always in the same place, as the Sun does in the center of our system. The probability, therefore, is that each of those fixed stars is also a Sun, round which another system of worlds or planets, though too remote for us to discover, performs its revolutions, as our system of worlds does round our central Sun. By this easy progression of ideas, the immensity of space will appear to us to be filled with systems of worlds; and that no part of space lies at waste, any more than any part of our globe of earth and water is left unoccupied.