Halley, A Synopsis of the astronomy of comets
At lenght, came the prodigious Comet
of the Year 1680 which descending (as it were from an infinite Distance)
perpendicularly towards the Sun, arose from him again with as great
, (which was seen for four Months
by the very remarkable and peculiar Curvity of its Orb (above all others)
gave the fittest Occasion for investigating the Theory of its Motion.
And the Royal Observatories, at Paris and Greenwich, having been for
some Time founded,
and commited to the Care of most excellent Astronomers,
the apparent Motion of this Comet
accurately (perhaps as far as human skill cou'd go)
observ'd by Mr. Cassini and Flamsteed.
But, as far as Probability from the Equality of Periods, and similar
Appearence of Comets
, may be urged as an Argument,
the late wondrous Comet
of 1680 seems to
have been the same,
which was seen in the Time of our King Henry I. Anno 1106,
which began to appear in the West about Middle of February,
and continued for many Days after, with such a Tail as was seen in
that of 1680.
And again, in the Consulate of Lampadius and Orestes, about the Year
of Christ 531,
such another Comet
appeared in the West,
of which Malela, perhaps an Eye-Witness,
relates that it was a great and fearful Star;
that it appeared in the West, and emitted upwards from it a long white
Beam; and was seen for twenty Days.
The Interval, between this and that of 1106, is nearly equal to that
between 1106 and1680, about 575 years.
And, if we reckon backward such another Period,
we shall come to the 44th Year before Christ, in which Julius Caesar
and in which there appear'd a very remarkable Comet
mentionnend by almost all the Historians of those Times.