opinion again was laught at by others, and rejected as ridiculous, who thought it impossible that one immaterial should produce another; and believed that both the light and heat of the Sun proceeded from a swift Circular motion of the Æthereal Globules, which by their striking upon the Optick nerve, caused light, and their motion produced heat: But neither would this opinion hold; for, said some, then it would follow, that the sight of Animals is the cause of light; and that, were there no eyes, there would be no light; which was against all sense and reason. Thus they argued concerning the heat and light of the Sun; but, which is remarkable, none did say, that the Sun was a Globous fluid body, and had a swift Circular motion; but all agreed, It was fixt and firm like a Center, and therefore they generally called it the Sun-Stone. Then the Empress asked them the reason, Why the Sun and Moon did often appear in different postures or shapes, as sometimes magnified, sometimes diminished; sometimes elevated, otherwhiles depressed; now thrown to the right, and then to the left? To which some of the Bird-men answered, That it proceeded from the various degrees of heat and cold, which are found in the Air, from whence did follow a differing density and rarity; and likewise from the vapours that are interposed, whereof those that ascend are higher and less dense then the ambient air, but those which descend are heavier and more dense. But others did with more probability affirm, that it was nothing else but the various patterns of the Air; for like as Painters do not copy out one and the same original just alike at all times; so, said they, do several parts of the Air make different patterns of the luminous Bodies of the Sun and Moon: which patterns, as several copies, the sensitive motions do figure out in the substance of our eyes. This answer the Empress liked much better then the former, and enquired further, What opinion they had of those Creatures that are called the motes of the Sun? To which they answered, That they were nothing else but streams of very small, rare and transparent particles, through which the Sun was represented as through a glass: for if they were not transparent, said they, they would eclipse the light of the Sun; and if not rare and of an airy substance, they would hinder Flies from flying in the Air, at least retard their flying motion: Nevertheless, although they were thinner then the thinnest vapour, yet were they not so thin as the body of air, or else they would not be perceptible by animal sight. Then the Empress asked, Whether they were living Creatures? They answered, Yes: Because they did encrease and decrease, and were nourished by the presence, and starved by the absence of the Sun.