ON THE NATURE OF THE SUN. 19 



mallows, indentations, and pores would be filled up, and the 

 ridges and the nodules would fubfide almoft inftantly. 

 Whereas many openings have been known to laft for a whole 

 revolution of the fun, and extenfive elevations have remained 

 fupported for feveral days. Still lefs could thefe phenomena 

 confiit with the fuppofition of elaftic fluidity. It remains, and confequently 

 therefore, fays he, for us to admit this mining matter to exift c j ouds% 

 in the manner of empyreal luminous or phofphoric clouds, re- 

 ading in the higher regions of the folar atmofphere. In fup- 

 port of this notion he gives the following obfervations. 



Changes in the folar clouds happen continually. There Rapid /ketch of 

 are two different regions of folar clouds, the lower of which of * h p e JJJfJfoJ. 

 confifts of clouds lefs bright than thofe which compofe the face, 

 upper ftratum. The inferior clouds are opaque, the colour of cl "™ d inous 

 all the fhallows being the fame, and confequently not affected Dark or pla- 

 by the caufe which acts upon the upper flratum when fhallows netar y clouds- 

 are generated. By a contrivance for the ufe of his photometer, 

 he found that if the fuperior felf-luminous clouds of the fun 

 throw the fame quantity of light on the inferior region of 

 opaque folar clouds as they fend to us, thofe inferior clouds, 

 of which the mallows are compofed, reflet"! about 469 rays 

 out of 1000 they receive ; but that the folid furface of the fun 

 feen in the openings reflects no more than about 7. The in- Other fatls and 

 dentations are planetary clouds, reflecting light through the a PP cawnces » 

 open parts of the corrugations, and thofe opaque inferior 

 clouds probably fuffer but little of the light of the felf-luminous 

 fuperior clouds to urike the body of the fun. The motion of 

 the inferior clouds is feen through the openings as they pafs 

 along. The fuperior clouds are alfo feen to tranverfe the 

 fame apertures previous to their clofing. 



That the planetary clouds are of eminent ufe, is inferred by Ufe and confti* 

 recurring to the phenomena before recited. The planetary 5 U j!! on | 0f j he 

 atmofphere of the fun, its great height, its denfity, as inferred 

 from the power of gravitation, which is known to be twenty- 

 feven times fironger at the fun's furface than with us., and 

 mull accordingly condenfe the atmofpheric gafes, its agitation 

 fimilar to the winds of our planet, and the clear atmofpheric 

 fpace beneath the {hallows, are among the facts upon which 

 our philofopher extends his difcuflions. He repeats and am- 

 plifies his remarks refpeCting the operation of the gas, which 

 is flated to pa fs from the fun itfelf upwards to the region of 



C 2 the 



