"But while I was upon this Enquiry (_of the Obliquity of the Ecliptic_) I was surprized to find the Latitudes of three of the principal Stars in the Heavens, directly to contradict the supposed greater Obliquity of the Ecliptic, which seems confirmed by the Latitudes of most of the rest; they being set down in the old Catalogues, as if the Plane of the Earth's Orbit had changed its Situation amongst the fixed Stars, about 20′ since the Time of _Hipparchus_, particularly all the Stars in _Gemini_ are put down, those to the Northward of the Ecliptic, with so much less Latitude than we find, and those to the Southward, with so much more southerly Latitude; and yet the three Stars _Palilicium_, _Sirius_, and _Arcturus_, do contradict this Rule: For by it, _Palilicium_, being in the Days of _Hipparchus_, in about 10 gr. of _Taurus_, ought to be about 15′ more southerly than at present, and _Sirius_ being then in about 15 gr. of _Gemini_, ought to be 20′ more southerly than now; yet _Ptolomy_ places the first 20′, and the other 22′ more northerly in Latitude than we now find them: Nor are these the Errors of Transcribers, but are proved to be right by the Declination of them set down by _Ptolomy_, as observed by _Timocharis_, _Hipparchus_, and himself; which shew, that these Latitudes are the same as those Authors intended. As to _Arcturus_, he is too near the Equinoctial Colour, to argue from him concerning the Change of the Obliquity of the Ecliptic; but _Ptolomy_ gives him 33′ more North Latitude than he is now found to have; and that greater Latitude is likewise confirmed by the Declinations delivered by the abovesaid Observations: So then these three Stars are found to be above half a Degree more southerly at this Time than the Antients reckoned them. When, on the contrary, at the same time, the bright Shoulder of _Orion_, has, in _Ptolomy_ almost a Degree more southerly Latitude than at present, what shall we say then? It is scarce to be believed, that the Antients could be deceived in so plain a Matter, three Observers confirming each other. Again, these Stars being the most conspicuous in Heaven, are in all Probability the nearest to the Earth; and if they have any particular Motion of their own, it is most likely to be perceived in them, which in so long a Time as eighteen hundred Years, may shew itself by the Alteration of their Places, though it be intirely imperceptible in the Space of one single Century of Years: Yet, as to _Syrius_, it may be observed, that _Tycho Brahe_ makes him 2 Min. more northerly than we now find him; whereas he ought to be above as much more southerly from his Ecliptic (whose Obliquity he makes 2′½ greater than we esteem it at the present) differing in the Whole 4′½. One Half of this Difference may perhaps be excused, if Refraction were not allowed in this Case by _Tycho_; yet 2 Min. in such a Star as _Syrius_, is somewhat too much for him to be mistaken in.