2 Signs in the
_Zodiack_: And of that, which in two daies ran through eight Signs: and of
another, which in 48 daies posted through all the Signs, _contra seriem_.
Which how it can be explicated upon the supposition of the Earths standing
still, and upon the denying of the annual Motion thereof, he understands
not at all. {106}

He refers to his _Cometography_ these Disquisitions: whether all Comets (in
their innate Motion) move equal _spaces_ in equal _Times_? which is the
swiftest, and which the slowest Motion they are capable of? what the cause
of this acceleration and retardation of their true Motion?

He puts it out of doubt, that they are in the _Sky_ it self, producing
reasons for it that are very considerable, and alledging amongst others,
That the _Parallaxes_ doe clearly evince it, which he finds far less in
Comets, then in the _Moon_, yea then sometimes in the _Sun_ it self. Where
he also represents, That he hath deduced the _Horizontal Parallax_ of this
very Comet from one onely Observation, made _Feb._ 4. _st. n._ by which he
found, That then it was distant from the Earth 5000 Semidiameters of the
same, or 4300000 _German_ miles. From this distance from the earth, he
deduces, That on that Day when it was so remote from the Earth, its true
_Diameter_ was 2560 _German_ miles, which is three times bigger then the
Diameter of the Earth, and almost six times bigger then that of the Moon,
whose Diameter, according to his _Theory_, is 442 _German_ miles.

He finds the _Matter_ of Comets to be in the _AEther_ it self, making the
_AEther_ and the _Air_ to differ only in purity, and esteeming, That the
_Planets_ do emit their Exhalations, and have their _Atmospheres_ like unto
our Earth. Where he affirms, That the Sun alone may cast out so much Matter
at any time in one year, as that thence shall be produced not one or two
Comets, equallizing the Moon in Diamiter, but very many; which if so, what
contribution may not be expected from the other Planets?

Of this Cometical Matter, he thinks, That first it is by little and little
gathered together, then coagulated and condensed, and thereby reduced to a
less Diameter; but then, after a while it resolves again, and grows dilute
and pale, and at last is dissipated. And accordingly he affirms, That he
hath observed the Head of this Comet at first more confused, thin and pale,
afterwards clearer and clearer. {107}

He conceives, That all Comets do respect the _Sun_ as th