VOL. XXVII.] PHILOSOPHICAL TRANSACTIONS. ^25 



which I suppose surrounds the sun, as well as our globe, and the moon mani- 

 festly ; and in all probability, every planet of this our solar system. 



From what has been said, we may give a reason, why there are sometimes 

 spots frequently on the sun, and sometimes none in many years. One thing I 

 believe there is in this, that there may be spots, but not always seen. But 

 there are doubtless great intervals sometimes when the sun is free ; as between 

 the years 1660 and 167I} 1 676 and l684; in which time spots could hardly 

 escape the sight of so many curious observers of the sun, as were then per- 

 petually viewing him with their telescopes in England, France, Germany, Italy, 

 and all the world over ; whatever might be before, from Scheiner's time. The 

 reason then of this long disappearance of the spots, I take to be from the want 

 of extraordinary eruptions in that fiery globe. The sulphureous, or other 

 matter, or pabulum of those eruptions, is spent or dissipated, and that globe 

 continues in its natural ordinary burning state, till there happens to be a fresh 

 collection of smoking, displosive, and extraordinary matter, to cause a new 

 eruption. Which eruptions generally happen between what we may call the 

 sun's tropics, or in his torrid zone : for I never observed any spots to be near 

 the sun's poles. And the spots in Scheiner's cuts are all about the middle zone 

 of the disk. The greatest evagation I ever observed of them, was March 8, 

 170^ : on which day, besides the dark spots in the usual zone, I perceived some 

 faint spots, scarcely visible, much nearer the southern pole than I ever had seen 

 them. But this was doubtless in some measure owing to the position of the 

 earth in respect of the sun, as well as to the southerly place of the spots on 

 him : for, about the equinoxes, the spots seem to march pretty far towards the 

 poles of the sun. Having thus observed what part of the sun the spots com- 

 monly possess, I shall next take notice of their stages and path over the sun. 

 That the sun moves round his own axis, is manifest, from the motion of the 

 spots. And that the spots seem to traverse the sun, sometimes in straight 

 lines, sometimes in curve lines, curved this way and that way, is as manifest 

 also, and well known to the curious. 



All these particulars are confirmations of what I said, that the solar spots are 

 no other than a smoke rising out of the body of the sun. Of which opinion 

 I have been almost ever since I first observed them, and find that I am not sin- 

 gular in this opinion, as I shall show from the following letter (which with some 

 others is lately fallen into my hands) from the admirable Mr. Crabtrie, to the no 

 less admirable Mr. Gascoigne, the inventor of the micrometer. 



The beginning of the letter has been torn off; but I find by that part of it 

 that is left, it was Mr. Crabtrie's first letter to Mr. Gascoigne, and that the 



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