By the same Observation a much greater Error is amended in the Latitude of _Aleppo_, in the _Rudolfine_ Tables of _Kepler_, who supposes _Aleppo_ to have been the ancient _Antiochia ad Taurum_, and accordingly places it Lat. 37. _deg._ 20 _min._ wherein he is followed by _Bullialdus_ and others; and several Maps have copied the Mistake. But a much greater use of it is, that thereby we are assured, that the City of _Aracta_, wherein _Albatani_ made the Observations we have Publish'd in the _Philosoph. Transact. Numb._ 204. was, without doubt, the same which is now called _Racca_ on the _Euphrates_; of which Town an Account may be seen in _Rauwolf_'s Voyages, and which was not many Miles below the Place where our Travellers first came on the River: And if _Arecca_, in the Language of this Country, relates to Victory (as is said in _pag. 143._) it was, doubtless, anciently the City _Nicephorion_, built by _Alexander_ the Great; with which the Situation exactly agrees. The Latitude thereof was observed by that _Albatani_ with great accurateness, about eight hundred Years since; and therefore I recommended it to all that are curious of such Matters, to endeavour to get some good Observation made at this Place, to determine the Height of the Pole there, thereby to decide the Controversie, whether there hath really been any Change in the Axis of the Earth, in so long an Interval; which some great Authors of late, have been willing to suppose. And if any curious Traveller, or Merchant residing there, would please to observe, with due care, the Phases of the Moons Eclipses at _Bagdat_, _Aleppo_ and _Alexandria_, thereby to determin their Longitudes, they could not do the Science of Astronomy a greater Service: For in and near these Places were made all the Observations whereby the middle Motions of the Sun and Moon are limited: And I could then pronounce in what Proportion the Moon's Motion does Accelerate; which that it does, I think I can demonstrate, and shall (God willing) one Day, make it appear to the Publick. * * * * * The _Philosophical Reader_ is desired to excuse our breaking in upon the Subject of these Tracts, by intermixing Historical and Philological Matters, as also our exceeding the Bounds of an Extract: But we hope the Curiosity of the Subject, joyned to the Desires of the _Royal Society_, may make an easie Apology suffice. There may be many other Instructive Remarks made thereon, which still deserve the Consideration of the Learned, and from such the Publick may yet expect a further Account. _A Voyage of the Emperour of _China_ into the Eastern _Tartary_, Anno. 1682._