As to the _Hypothesis_ of _Georg. Domenico Cassini_, touching the motion of the _Comet_ about the _Great Dog_ in a Circle, whose Centre is in a streight line drawn from the Earth through the said Star, I believe it will shortly be publish'd in print, as a thought I lighted upon in discoursing with one of my Friends, who did maintain, that it turned about a Centre, because that its _Perigee_ had been over against the _Great Dog_, as I had noted in my _Ephemerides_. This particular I did long since declare to many of my acquaintance, whereof some or other will certainly do me that right, as to let the world know it by the Press. I have added an Observation, which I find not, that Signior _Cassini_ hath made, _viz._ that there was ground to think, that the _Comet_ of 1652. was the same with the present, seeing that besides the parity of the swiftness of its motion, the _Perigee_ thereof was also over against the _Great Dog_, if the Observations extant thereof, deceive not. But, to make it out, what ground I had for these thoughts, I said, that if they were true, the Comet must needs acomplish its revolution from 10. to 12. years, or thereabout. But, seeing it appears not by History, that a Comet hath been seen at those determinate distances of time, nor that over against the _Perigee_ of all the other Comets, whereof particular observations are recorded, are alwaies found Stars of the first Magnitude, or such others, as are very notable, besides other reasons, that might be alledged, I shall not pursue this speculation; but rather {19} suggest what I have taken notice of in my reflexions upon former Comets, which is, that more of them enter inter our Systeme by the sign of _Libra_ and about _Spica virginis_, than by all the other parts of the Heavens. For, both the present Comet, and many others registred in History, have entred that way, and consequently passed out of it by the sign _Aries_, by which also many have entred.