end the Ktihirc of its Light. 41 



that one fide of it has the fame brielitncfs as the fnlar light 

 itfclf, we then no longer fee an eminence, but only a faint 

 fpot produced bv the half (liadow on the other fide. But it' 

 the dirci.Hion of the ftrongcCt half fliadows towards anv part 

 of the fun's dilk be once known, we may then venture to 

 examine the greatctl. collection of luminous facula?, and di- 

 ftinguifli them with the bed fuccefs. They then lofe their 

 rtrango appearance; ; and the eye becomes convinced that an 

 afl'eniblage of eminences and plains could exhibit fuch an 

 appearance onlv bv a light proccediiAg from diO'ercnt fide?, 

 though with various degrees of ftrenglh. J'cfides, it may 

 fomenme? be the cafe that the light may be higher, nearer, 

 or at a trreiUi-r difhmce in one diUrict than another; and 

 therefore it i.~ difHcult, under all thcle circumllances, to form 

 a right judgment of an objeft in the fun. 



'I'lie fun, therefore, mnft be inclofcd in a luminous cover- 

 ing, or furrounded by an atmofphcre of light — an idea fird 

 Itartcd bv Mr. IJode; but the ])eculiar quality of it remains 

 to be more fullv inveliigated. A globular covering of boiling 

 light fecnis to be too moveable to produce the above phieno- 

 niena. The irregular fpreading of the furrounding flame 

 vould every moment chanue the fccne; as a mixtiu'e of lu- 

 minous matter wiih the folar atmofphere would give it an 

 obfcure appearance, and be contrary to the fmoothnefs of 

 that line by which the folnr dilk is bounded. 



The fun may be confidered as an opake body of ilfelf, and 

 furrounded bv an atmofphere almoft fimilar to ours; but the 

 luminous matter as an uncommonlv fine fluid, which, like 

 liquid naphtha, floats on this atmofphere, and, on account of 

 Its great lightnefs, can never fink down under any clrcum- 

 flanccs \vhate<'er. 



The atmofphere of the fun, bv his rotation, being raifeJ 

 •liiglier under the equator, will be depreffed towards the polar 

 regions. The luminous matter is attracted from the celettial 

 cxpanfe; and this hvpf)tbefis, which has been adopted by 

 many, appears to be the true one, bccaufe the phienomena 

 on the f'urface of the fun can be befl explained by it. It 

 niufl however be premifed, that no moi-e luminous matter is 

 attractt-d than may be nceefi'ary to form ahnoli a total cover- 

 ing to the fun; and that, on account of t!',e continual infiujc 

 towards flie poles, it mull often iiapp' ii that the quantity 

 there will be diminiihed. Th!.^ is a confciiuenee of the thimr 

 itfelf; for, if it be admitted that the feparation of the lumi- 

 nous malt r is performed bv a chemical aflliutv, the e{Te6l of 

 which is facilitated by the fun's rotat. '1:1, the atlradion will 

 ^eafe when t^ic folur aimofph«r9 has imbibed a fufficient 



quantity. 



