[Footnote AD: Betwixt the Sword and Girdle of _Orion_.] [Footnote AE: Vide _Reitha_.] This, tho' I presume to call it at present only meer Hypothesis, will in a great measure account for the excessive Changes in the Constitution of our Air and Atmosphere, which we often find very unnatural to the Season; also be a Means perhaps of reconciling the vast Disproportion so very remarkable betwixt the Sun and the lesser Planets, and many other Circumstances in the System of no small Consequence in Astronomy: One of which Particulars you have frequently expressed a great Mistrust and Disapprobation of, as suspecting some kind of a Fallacy in the Computation; and the other is Matter of general Complaint, being by many attributed to a Change in the Direction of the Earth's Axis[AF]; and by some, especially the Vulgar, to too near an Approximation of the Earth to some one of the celestial Bodies. But all this will very naturally be accounted for by the Levity, or expanding Quality of the Sun's circumambient Flame, or Atmosphere; and hence, according to its various State, being more condensed, or rare, we may have Heat or Cold in the greatest Extream, and alternately so, in a perpetual Vicissitude. [Footnote AF: Which, through Ignorance of the true Case, is commonly called a Shock, a Brush, or Shove.] The Truth of this Doctrine will evidently appear from the Observations of the Sun's Diameter through the Year 1660, by the indefatigable _Mouton_: And, I must own, I am not a little surprized to find that no Conclusions have been drawn from them of this Kind. I am perswaded, if you once compare those Numbers, you will be very far from thinking this an improbable Suggestion. But this Digression has led me a little too far from the _Via Lactea_, and too near home again; I must now think of returning to the Stars, and my next Endeavours must be to give you some Idea of the Number of them. Through very good Telescopes there have been discovered in many Parts of this enlightened Space, and even out of it, several thousand Stars in the Compass of one square Degree; in particular near the Sword of _Perseus_, and in the Constellations of [AG]_Taurus_ and _Orion_. [Footnote AG: _Galilæo_ in one cloudy Star of this Constellation, discovered no less than twenty-one, and in that of the _Præsepe_ thirty-six.] PLATE XV.