710 PHILOSOPHICAL TRANSACTIONS. [aNNO 1672« 



April the 5th, at eight o'clock in the evening, the comet had passed the 

 northern ear of Taurus, and was equally distant from the upper star of the 

 northern ear, and from that which was on the front of Taurus. He was also as 

 distant from the inferior star of the ear of Taurus, as this star is from the next 

 westward, by Tycho called inferior praecedentis lateris quadrilateri, and a straight 

 line, drawn through the comet and the upper star of the ear, made an almost 

 right angle with another line, drawn from the comet to the inferior of the two 

 small stars that are above the eye of Taurus. This place being transferred to the 

 map of the fixed stars, the comet was found at 6° 18' of Gemini, in lat. 3° 4l'. 



April the 6th, at eight o'clock in the evening, the comet was found at 7° 25' 

 of Gemini, in lat. 2° 45'. 



April the 7th, at nine o'clock in the evening, the comet was in 8° 30' of Ge- 

 mini, in lat. 1° 56'. 



SiGNOR Cassini's reflections on the foregoing Observations. 



All the places of the comet fall into a line little. differing from an arch of a 

 great circle, which cuts the ecliptic in 10° 45' of Gemini, and which consequently 

 has its greatest latitude in 10^45' of Pisces; which latitude is betvteen Sg and 

 40 deg. N. The same circle cuts the equator at 101° of the vernal section 

 eastward, and its greatest declination from the equator northward, is 38 -i- 

 degrees. 



Having chosen two of our first observations, and having taken a mean be- 

 tween the first observations of the mathematicians of la Fleche, we have found 

 by this method, that the comet had been in his perigee, March 12, at 8 o'clock 

 in the morning. That in that time, which was that of its greatest apparent 

 celerity, it made about 2° 32' a day in the great circle of its apparent motion, 

 and ^lll^, of its perigee distance in the line of its equal motion. That it was in 

 its greatest declination the ] 1th and 12th of March; and that at that time it 

 passed through the inferior meridian at about two o'clock after midnight. 



It is a thing worth observing, that this comet keeps its course almost like that 

 of the 2d comet of 1665, and of another of 1577, observed by Tycho. For 

 they have passed through almost the same constellations, though this be more in- 

 clined northward, and cut the ecliptic 5 or 6 degrees more forward than that of 

 1665. So that it seems that in this place of the Heavens there is^ as it were, a 

 zodiac for comets. 



An Account of some Boohs. N° 82, p, 4050. 

 I. De Resistentia Solidorum Alexan. Marchettij in Pisana Academia Phil. 

 Prof. Excusum Florentias 1665, inthin4to. 



