13 ON THE NATURE OF THE SUN, 



Of Noduks. 



Nodules, or Nodules are fmall, but highly elevated luminous places, 



fmall elevations © J r 



of the luminous - 1 nc y may be ridges four fhortened. 

 matter. 



Of Corrugations. 



Corrugations are The corrugations confift of elevations and depreffions. 



Imaller elevations _,, , ° ; 



and depreffions * lie y nave a mottled appearance, confining of dark and 



of the luminous bright places. Many of the dark places are not round, but a 

 little extended in different directions, and appear to be lower 

 than tlie bright places. On favourable days the corrugated 

 furface prefents its elevations and depreffions as diftindtly as 

 the rough furface of the moon. They extend over the whole 

 furface of the fun. Difperfed ridges or nodules make corruga- 

 tions. The corrugations change their fhape and fituation ; 

 they increafe, diminifh, divide, and vanifh quickly. Fig. 18 

 exhibits a fmall fketch of the place of phenomena obferved by 

 the author and Dr. Wilfon, in which the rapid changes were 

 correfpondently obferved. 



Of Indentations. 



Indentations of The dark places of corrugations are indentations. That 



matter. tne y are not mucn depreffed, is deduced from their vifibility 



pretty near the margin of the fun. The indentations go 



down at the fides like circular arches, but their bottom* are 



occafionally flat. See Fig. 19. Some indentations have no 



openings, others have. The corrugations are of all fhapes, 



chiefly lengthened. The indentations are. of the fame nature 



as fhallows ; are of different fizes ; fometimes containing very 



- fmall openings, and fometimes changing to openings. They 



are extended over the whole furface of the fun, and with low 



magnifying powers they appear like points. 



Of Pores. 



Port*. Tl>e low places of indentation arc pores. They occafionally 



increafe, and become openings : and frequently they vanifh 

 in a fliort time. 



Of the Region,? of Solar Clouds. 

 The finning D r# Herfchel obferves that the phenomena before dc- 



Sn cannot be a fcribed could not appear, if the fhining matter ot the fun were 

 liquid or a gas 3 ^ liquid, becaufe by the laws of hydroftatics the openings, 



ihallows, 



