40 Ohfervat'ions on the Spots of the Sun, 



agreeable furprifc, as it exhibits fomctliing very . different 

 from what we fee in thofe parts of furrounding nature which 

 are neaieft to iis. With a Herfchcl's tclcfcope of leven feet, 

 one beholds with aftoniflinK-nt, and very diltinftjy, in thofe 

 fpots in the middle of the fim's orb, parts befct with little 

 hills feparated by valleys, and finglc mountains, of a propor- 

 tional height, which jirojeft firong fliadows. It is worthy of 

 remark, that thefe objefts have as diminiflicd an appearance 

 as when one looks at things from a great height. The caiifc 

 of this is to be fought for in the (ituatton of the light which 

 falls on them, and belongs to thofe optical deceptions that 

 murt occur fo frequently in obferving the funf and on a know- 

 ledsre of them depends the whole feeret ot forming a proper 

 judgment refpefting the folar bodies. 



■ The finenefs of the delineation, the fcenie appearance, 

 and the regularity of thefc objet^ts, induce one to believe that 

 folar landlcapes are here ac^hiallv reprefcnted ; and totally de- 

 ftroy the idea of the fun being a flaming body; for it is im- 

 poflible that the irregular movement of flame could ever 

 produce fuch fcenes. Thefe parts are, at times, of a more 

 whitidi colour; but it ought to be particularly remarked that 

 they have a fomevvhat dimmer light than the reft of the fun's 

 orbit, which is ever)' where luminous. If the divifion of the 

 Jiohts and fliadows, the kind of illumination, and the cra- 

 dation of the (liades, be accurately obferved and examined, 

 we fhall be obliged to admit that thefe facula; in the fun are 

 landfcapes. 



The mod important obfervation here is, that when there 

 are a group of lueh landfcapes the fliadows are almoll always 

 projected to one fide, and are fliarp-pointed. This circum- 

 Itance ferves to render clear to the eye a confufcd mixture of 

 fpots. 



Let one fearch out, in the neighbourhood of fuch groups, 

 fmall, fingle, infulated I'pots, and obferve whether there is 

 feen near them a weak gradation of fliade, or a luminous 

 vapour which is very familiar to us, and which fliows that th^-. 

 light illuminates an eminence on all fides, but not with equal 

 ftrength. If the eye is once accu(U)|ned to the efteft that 

 hence arifes, it can with great eafe convert an often exceed- 

 inglv compound mixture of dark parts and luminous fpots 

 into well arranged images. 



There are certainly cales in obferving the fun when draftf- 

 jnen and painters only could be able to arrange properly the 

 mixture of faint fpots, and to obviate the deception which 

 arifes from half fliadows. When an eminence, for example, 

 is fo firongly enlightened by the himinous matter near it, 



■ ' , -■ . that 



