this _first_ more particularly, and more fully than he hath done
here.

In this Account he represents the Rise, Place, Course, Swiftness, Faces and
Train of this Comet, interweaving his Conceptions both about the Region of
Comets in general (whether in the _Air_, or the _AEther_?) and the Causes of
their Generation: In the search of which latter, he intimates to have
received much assistance from his _Telescope_.

He observes this Comet not before _Decemb._ 4/14, (though he conceives it
might have been seen since _Novemb._ 23 _st. n._) & he saw it no longer
then _Feb._ 3/13: though several others have seen it both sooner, and
later: and though himself continued to look out for it till _March_ 7. _st.
n._ but fruitlesly, whereof he thinks the reason to have been its too great
distance and tenuity.

{105}

He finds, its apparent Motion was not made in a _Just_ great Circle, but
deviated considerably from it; and conceives, that every Comet falls to
this deviation, when this apparent Motion grows slow, and the Star becomes
Stationary (which, as he saith, it doth in respect of the _Ecliptick_, not
its own _Orbite_,) Here he observes, That from _Decemb._ 8/18, to _Decem._
30. _Jan._ 9. its course was almost a great Circle: but that _then_ it
began to deflect from that Circle towards the _North_; so that afterwards,
with a very notable and conspicuous Curvity, it directed its course towards
_Primam Arietis_: Of which deflection, he ventures to assign the cause from
the Cometical Matter, the various position and the distance of the Comet
from the Earth and the Sun, the annual Motion of the Earth, and the
impressed Motion, and the inclination of the _discus_ of the Cometical
Body.

He is pretty positive, that without the _annual Motion_ of the _Earth_, no
rational Account can be given of any Comet, but that all is involved with
perplexities, and deform'd by absurdities.

He inquires, since all Comets have the peculiar _Ingenite_ Motion, what
kind of Line it is, they describe by that Motion of their own? whether
circular, or streight, or curve, or partly streight and partly curve? And
if curve, whether regular or irregular? if regular, whether Elliptick, or
Parabolar, or Hyperbolical? He answers, That this Motion is _Conical_; and
judgeth, that by the _Conick_ path all the _Phaenomena_ of Comets can,
without any inconveniency, be ready solved; even of that, which (by
History) in fifty daies, passed through more then the 1