482 THE MATHEMATICAL PRINCIPLES [BOOK 111. in New England, it was found in about ^l 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 ^l 1° 50' ; and therefore at 5h. morn ing at London, the comet was in iU 3° 5' nearly. The same day, at 6^h. in the morning at London, Dr. Hook observed it in about nt 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 Lt>oi\is at a very small distance therefrom. The right line through Cor Leonis and Spica ^ did cut the ecliptic in ^ 3° 46' at an ano-le of 2° 51' ; and if the comet had been in this line and in W. 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 ^l7, that is, about 1° 30'. But by the agreement of Hook, Montenari, and Align, the latitude was continually increasing, and therefore must now, on the 22ci be sensibly greater than t° 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 W, 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 op position of the sun towards the north. Nov. 23, O. S. at 51. morning, at Nuremberg (that is, at 4^h. at Lon don), Mr. Zimmerman saw the comet in ^t 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 TCI 1?° 52' on the north side of the right line through Cor Leonis and Spica W, and therefore its latitude was something less than 2° 38' ; and since the latitude, as we said, by the concurring observations of Montenari, A/io-0, 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. Ponthwns and Galletins 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 H°. The observations of Ponthceus and Cellius are more rude, espe cially those which were made by taking the azimuths and altitudes ; as are also the observations of Galletins. 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