heavens; how in the meantime some of its parts must compose an earth and
some planets and comets, and others a sun and fixed stars. And, making a
digression at this stage on the subject of light, I expounded at
considerable length what the nature of that light must be which is found
in the sun and the stars, and how thence in an instant of time it
traverses the immense spaces of the heavens, and how from the planets and
comets it is reflected towards the earth. To this I likewise added much
respecting the substance, the situation, the motions, and all the
different qualities of these heavens and stars; so that I thought I had
said enough respecting them to show that there is nothing observable in
the heavens or stars of our system that must not, or at least may not
appear precisely alike in those of the system which I described. I came
next to speak of the earth in particular, and to show how, even though I
had expressly supposed that God had given no weight to the matter of which
it is composed, this should not prevent all its parts from tending exactly
to its center; how with water and air on its surface, the disposition of
the heavens and heavenly bodies, more especially of the moon, must cause a
flow and ebb, like in all its circumstances to that observed in our seas,
as also a certain current both of water and air from east to west, such as
is likewise observed between the tropics; how the mountains, seas,
fountains, and rivers might naturally be formed in it, and the metals
produced in the mines, and the plants grow in the fields and in general,
how all the bodies which are commonly denominated mixed or composite might
be generated and, among other things in the discoveries alluded to
inasmuch as besides the stars, I knew nothing except fire which produces
light, I spared no pains to set forth all that pertains to its nature, --
the manner of its production and support, and to explain how heat is
sometimes found without light, and light without heat; to show how it can
induce various colors upon different bodies and other diverse qualities;
how it reduces some to a liquid state and hardens others; how it can