Page:Philosophical Transactions - Volume 001.djvu/9

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ginning of March, if we see it so long, the said motion shall not exceed 4 minutes, and so shall be still diminishing; except the Comet become Retrograde, which, as very important, he would have well observed; as also, whether it motion will be about the end more or less swift, than he hath calculated it.

He subjoyneth, that the greatest way, which this Star could make in 24 hours, hath been 13.d.25'; and in one houre, about 34's and thinking it probable, that about the time, when it made so much way, it should be nearest to the Earth, he concludeth that its motion in 24. hours must be, in its least distance from the Earth, as about 3. to 14, or 1. to 42/3, and that its motion in one hour was to be to the same least distance, as about 1. to 1021/7.

But that, which he judgeth most rewarkable, is, that he found by his Calculation, that the said least distance should be on the 29. of December, when the Comet was opposite to the Suns which he does not know whether it may not serve to decide the grand Question concerning the Motion of the Earth.

He taketh further notice, that the Tayl of the Comet was to turn Westward, with a point to the North, until the 29. of December, at which time it was to be opposite to the Sun, and that then the said Tayl was to look directly North; but that, after that time, the Tayl was to turn Eastward, and continure to do so, until it disappear; and that it shall draw a little towards the North, until the 8. or 10. of February, at which time the Tayl is to be parallel to the Æquator, as if the Comet be yet seen for some time after, the Tayl shall go a little lower towards the South, but grow smaller.

He finds by his Hypothesis, that on the 2. of December, which is the first observation, that he hath heard of, this Star was to be about 7. times more remote from the Earth, than when it was in its Perigeum; and that it will be again in an equall remoteness from the Earth, on the 27. of January, so that he is of opinion, that in case this Comet have not been seen before the 2 of December, it will not be seen any more after the 27. of January.

He wishes above all things, that it might be very exactly observed, at what Angle the way of the Comet cuts the Æquator, and, most of all, the Ecliptick, that so it may be seen, whether

there