The Emperor and the Queen Mother pretend moreover by this Journey, to avoid the excessive Heats which are in _Pekin_, in the Summer during the Dog-days. For in this part of _Tartary_, there reigns during the Months of _July_ and _August_ so cold a Wind, especially in the Night, that 'tis necessary to put on thick Cloths and Furs. The Reason that may be assigned for this so extraordinary Cold, is that this Region is very much elevated and full of Mountains: There is one among the rest, upon which we continually ascended, for the space of 5 or 6 Days March. The Emperor being desirous to know how much it surmounted the Plains of _Pekin_, distant about 300 Miles; at our return (after having measured the height of above a hundred Mountains that lay in our Road) we found that it had 3000 Geometrical Pace of Elevation, above the Sea that nearest approached _Pekin_. The Salt Peter also with which these Countries abound, may contribute to this great Cold, which is so violent, that in digging the Earth to three or four Foot deep, there are fetched out Clods all frozen, and pieces of Ice. Divers of the Petty Kings of the Western _Tartary_, came from all sides for 300 Miles, and some for 500 Miles, together with their Children, to salute the Emperor. These Princes, who for the most part know none but by their own natural Language, which is very different from that of the Eastern _Tartary_: Took regard of us, with Aspects and Gestures of a goodness very particular. There were some among them, who had made a Journey to _Pekin_ to see the Court, and who had seen our Church. One or two Days before we arrived at the Mountain which was the boundary of our Journey, we met a Petty King very aged, who returned from accompanying the Emperor, he seeing us stayed with all his Retinue, and enquired by his Interpreter, which of us was called _Nauboaij_; one of our Servants having made a sign that it was I, this Prince accosted me with a great deal of Civility, and told me that for a long time he had known my Name, and that he had desired to know me. He spoke also to Father _Grimaldi_, with the same marks of Affection. The favourable Entertainment he gave us in this Re-encounter, gave some Reason to hope that our Religion might find an easie Entrance to those Princes, particularly if care be taken to insinuate into the Minds of those Princes, by the means of the Mathematicks: Which if there should at any time be a design to penetrate into their Country, the most sure way for divers Reasons, (which I have not the leisure to explain here) will be to begin the entrance with the other _Tartars_ more remote, which are not all Subjects of this Empire, from whom we may pass on to these, advancing by little and little towards _China_. During the whole Journey, the Emperor has continued to give us singular Tokens of his good Will, shewing us Favours in the sight of his Army, which he shewed to none besides.