628 PHILOSOPHICAL TRANSACTIONS. [aNNO I7II. 



none at all seen in the sun's hemisphere : and in both these cases, the outermost 

 planet of all would always in the space of 27 days, be seen in the same place, 

 being never obscured, none of the inferior being able to reflect light upon it. 

 Add hereunto, if any kind of reflection should make them to appear bright 

 like the sun, and so not distinguishable from the light of the sun, what should 

 hinder, but we should see them also bright bodies by the side of the sun, when 

 they are passing either by the west, or east side of the sun's body ? The light 

 being then reflected upon them by the inferior planets as well as at other times, 

 and that also upon much of that side of them which we should behold. 



" But if you wave this conceit, as insuflicient, and fly to your former, 

 that the swifter movers in the lower orbes, overtaking the slower in the higher 

 orbes, cause an appearance. To this I answer. J . The thing you suppose 

 seems to me neither necessary nor probjible, nor do I conceive why they should 

 not be seen, being themselves alone, as well as conjoined, seeing all other 

 stars and planets are so. 2. If it be because they are of a thin, transparent 

 substance, till many, being one behind another, make them to seem grosser ; 

 then they are not of the nature of other planets, as is proved in ^ and 9 ? who 

 of themselves appear dark bodies, when they come between us and the sun ; 

 nay, they must be more thin than our clouds, which will easily be seen between 

 us and the sun, and hides it from us. 3. If it be because they are so little, 

 that the imperfection of our glasses cannot discover one alone, there must be, 

 without doubt, many millions of them ; which how they can be included 

 within the compass of -^V of the 0's semidiameter, we shall consider anon. I 

 have seen one of an ordinary darkness, (yea darker than many greater) yet not 

 above b" diameter. If this consist of two, or many, of themselves invisible, 

 how many were in those which Gassendus saw of l-^' diameter ? 4. The figure 

 of these great ones (being necessarily composed of stars of such different orbes 

 and motions) would quickly vary, by reason of the diversity of their motions ; 

 like as we see in a flock of small birds. But fifthly, you say the furthest of 

 these orbes is not above -^ of the sun's semidiameter from its circumference. 

 But there would not, in that small space, be room enough for so many orbes of 

 planets, as have been seen at once. Which I prove thus. 1. Gassendus 

 aflfirms there are sometimes some of about the Vo- P^'*^ of the 's semidiameter ; 

 which is the whole space allowed by you for them all. And I myself have seen 

 of tV of the 0's semidiameter: and yet you must confess these great ones 

 could only be the conjunctions of some, not all. 2. There are many times seen 

 in the 0*s superficies, a great number of spots, whose diameters added together, 

 would do more than twice fill the space you speak of. I myself have seen it, 

 and so I believe have you. Gassendus affirms, there are sometimes 40 seen at 



