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u129Nov. 18, at 6h. 30' in the morning at Rome (that is, at 5h. 40' at London), Ponthæus observed the comet in ♎ 13° 30', with latitude 1° 20'[Pg 481] south; and Cellius in ♎ 13° 30', with latitude 1° 00' south. But at 5h. 30' in the morning at Avignon, Galletius saw it in ♎ 13° 00' with latitude 1° 00' south. In the University of La Fleche, in France, at 5h. in the morning (that is, at 5h. 9' at London), it was seen by P. Ango, in the middle between two small stars, one of which is the middle of the three which lie in a right line in the southern hand of Virgo, Bayers ; and the other is the outmost of the wing, Bayer's . Whence the comet was then in ♎ 12° 46' with latitude 50' south. And I was informed by Dr. Halley, that on the same day at Boston in New England, in the latitude of deg. at 5h. in the morning (that is, at 9h. 44' in the morning at London), the comet was seen near ♎ 14°, with latitude 1° 30' south.

Nov. 19, at at Cambridge, the comet (by the observation of a young man) was distant from Spica ♍ about 2° towards the north west. Now the spike was at that time in ♎ 19° 23' 47'', with latitude 2° 1' 59'' south. The same day, at 5h. in the morning, at Boston in New England, the comet was distant from Spica ♍ 1°, with the difference of 40' in latitude. The same day, in the island of Jamaica, it was about 1° distant from Spica ♍. The same day, Mr. Arthur Storer, at the river Patuxent, near Hunting Creek, in Maryland, in the confines of Virginia, in lat. °, at 5 in the morning (that is, at 10h. at London), saw the comet above Spica ♍, and very nearly joined with it, the distance between them being about of one deg. And from these observations compared, I conclude, that at 9h. 44' at London, the comet was in ♎ 18° 50', with about 1° 25' latitude south. Now by the theory the comet was at that time in ♎ 18° 52' 15'', with 1° 26' 54'' lat. south.

Nov. 20, Montenari, professor of astronomy at Padua, at 6h. in the morning at Venice (that is, 5h. 10' at London), saw the comet in ♎ 23°, with latitude 1° 30' south. The same day, at Boston, it was distant from Spica ♍ by about 4° of longitude east, and therefore was in ♎ 23° 24' nearly.

Nov. 21, Ponthæus and his companions, at in the morning, observed the comet in ♎ 27° 50', with latitude 1° 16' south; Cellius, in ♎ 28°; P. Ango at 5h. in the morning, in ♎ 27° 45'; Montenari in ♎ 27° 51'. The same day, in the island of Jamaica, it was seen near the beginning of ♏, and of about the same latitude with Spica ♍, that is, 2° 2'. The same day, at 5h. morning, at Ballasore, in the East Indies (that is, at 11h. 20' of the night preceding at London), the distance of the comet from Spica ♍ was taken 7° 35' to the east. It was in a right line between the spike and the balance, and therefore was then in ♎ 26° 58', with about 1° 11' lat. south; and after 5h. 40' (that is, at 5h. morning at London), it was in ♎ 28° 12', with 1° 16' lat. south. Now by the theory the comet was then in ♎ 28° 10' 36'', with 1° 53' 35'' lat. south.

Nov. 22, the comet was seen by Montenari in ♏ 2° 33'; but at Boston[Pg 482] in New England, it was found in about ♏ 3°, and with almost the same latitude as before, that is, 1° 30'. The same day, at 5h. morning at Ballasore, the comet was observed in ♏ 1° 50'; and therefore at 5h. morning at London, the comet was in ♏ 3° 5' nearly. The same day, at in the morning at London, Dr. Hook observed it in about ♏ 3° 30', and that in the right line which passeth through Spica ♍ and Cor Leonis; not, indeed, exactly, but deviating a little from that line towards the north. Montenari likewise observed, that this day, and some days after, a right line drawn from the comet through Spica passed by the south side of Cor Leonis at a very small distance therefrom. The right line through Cor Leonis and Spica ♍ did cut the ecliptic in ♍ 3° 46' at an angle of 2° 51'; and if the comet had been in this line and in ♏ 3°, its latitude would have been 2° 26'; but since Hook and Montenari agree that the comet was at some small distance from this line towards the north, its latitude must have been something less. On the 20th, by the observation of Montenari, its latitude was almost the same with that of Spica ♍, that is, about 1° 30'. But by the agreement of Hook, Montenari, and Ango, the latitude was continually increasing, and therefore must now, on the 22d, be sensibly greater than 1° 30'; and, taking a mean between the extreme limits but now stated, 2° 26' and 1° 30', the latitude will be about 1° 58'. Hook and Montenari agree that the tail of the comet was directed towards Spica ♍, declining a little from that star towards the south according to Hook, but towards the north according to Montenari; and, therefore, that declination was scarcely sensible; and the tail, lying nearly parallel to the equator, deviated a little from the opposition of the sun towards the north.

Nov. 23, O. S. at 5h. morning, at Nuremberg (that is, at at London), Mr. Zimmerman saw the comet in ♏ 8° 8', with 2° 31' south lat. its place being collected by taking its distances from fixed stars.

Nov. 24, before sun-rising, the comet was seen by Montenari in ♏ 12° 52' on the north side of the right line through Cor Leonis and Spica ♍, and therefore its latitude was something less than 2° 38'; and since the latitude, as we said, by the concurring observations of Montenari, Ango, and Hook, was continually increasing, therefore, it was now, on the 24th, something greater than 1° 58'; and, taking the mean quantity, may be reckoned 2° 18', without any considerable error. Ponthæus and Galletius will have it that the latitude was now decreasing; and Cellius, and the observer in New England, that it continued the same, viz., of about 1°, or °. The observations of Ponthæus and Cellius are more rude, especially those which were made by taking the azimuths and altitudes; as are also the observations of Galletius. Those are better which were made by taking the position of the comet to the fixed stars by Montenari, Hook, Ango, and the observer in New England, and sometimes by[Pg 483] Ponthæus and Cellius. The same day, at 5h. morning, at Ballasore, the comet was observed in ♏ 11° 45'; and, therefore, at 5h. morning at London, was in ♏ 13° nearly. And, by the theory, the comet was at that time in ♏ 13° 22' 42''.

Nov. 25, before sunrise, Montenari observed the comet in ♏ ° nearly; and Cellius observed at the same time that the comet was in a right line between the bright star in the right thigh of Virgo and the southern scale of Libra; and this right line cuts the comet's way in ♏ 18° 36'. And, by the theory, the comet was in ♏ ° nearly.

From all this it is plain that these observations agree with the theory, so far as they agree with one another; and by this agreement it is made clear that it was one and the same comet that appeared all the time from Nov. 4 to Mar. 9. The path of this comet did twice cut the plane of the ecliptic, and therefore was not a right line. It did cut the ecliptic not in opposite parts of the heavens, but in the end of Virgo and beginning of Capricorn, including an arc of about 98°; and therefore the way of the comet did very much deviate from the path of a great circle; for in the month of Nov. it declined at least 3° from the ecliptic towards the south; and in the month of Dec. following it declined 29° from the ecliptic towards the north; the two parts of the orbit in which the comet descended towards the sun, and ascended again from the sun, declining one from the other by an apparent angle of above 30°, as observed by Montenari. This comet travelled over 9 signs, to wit, from the last deg. of ♌ to the beginning of ♊, beside the sign of ♌, through which it passed before it began to be seen; and there is no other theory by which a comet can go over so great a part of the heavens with a regular motion. The motion of this comet was very unequable; for about the 20th of Nov. it described about 5° a day. Then its motion being retarded between Nov. 26 and Dec. 12, to wit, in the space of days, it described only 40°. But the motion thereof being afterwards accelerated, it described near 5° a day, till its motion began to be again retarded. And the theory which justly corresponds with a motion so unequable, and through so great a part of the heavens, which observes the same laws with the theory of the planets, and which accurately agrees with accurate astronomical observations, cannot be otherwise than true.

Page 129 of 154 · Mathematical Principles of Natural Philosophy, Isaac Newton , tr. Andrew Motte · Project Gutenberg