50 



The following definitions of these new terms, together with the 

 principal circumstances relating to those appearances, as deduced 

 from a long series of observations, will, it is hoped, sufficiently indi- 

 cate the contents of this section. Whoever peruses this paper must, 

 however, here recollect that Dr. Herschel has long considered the 

 sun as an opake habitable globe, possessed of an atmosphere in 

 which luminous clouds, ever varying in form and dimensions, are 

 continually floating, and produce the appearances of which the fol- 

 lowing is an enumeration. 



1. Openings, or places where the luminous clouds are removed. 

 When these are large, they have generally flats about them ; and the 

 small ones are without flats. They are also frequently attended by 

 ridges and nodules. New and incipient openings frequently break 

 out near former ones ; and they often change their figure, run into 

 each other, and turn into shallows, or other appearances of a different 

 description. 



2. Flats. These are described as planes depressed below the ge- 

 neral or brightest surface of the sun, or places from whence the lu- 

 minous solar clouds of the upper regions are removed. Their thick- 

 ness is visible at the edges of the openings : from the various changes 

 they undergo, it is inferred that they are occasioned by some emana- 

 tion, perhaps an elastic gas, coming out of the openings, which by 

 its propelling motion drives away the luminous clouds from the place 

 where it meets with the least resistance, or which by its nature dis- 

 solves them as it comes up to them. 



3. Ridges, or elevations above the general surface of the luminous 

 clouds of the sun, These generally accompany openings, and often 

 gather and disperse alternately. They are ascribed to some elastic 

 gas, acting below the luminous clouds, which first lifts them up, and 

 at last forces itself a passage through them by throwing them aside. 



4. Nodules. These are small but highly elevated luminous places. 

 They may frequently be ridges fore-shortened, and are probably in 

 all cases produced in the same manner. 



5. Crankles. These consist of elevations and depressions, which 

 produce a mottled appearance that often spreads over the whole disk 

 of the sun. They frequently change their shape, and situation^ and 

 may perhaps be occasioned by the expansion of ridges or nodules. 



6. The dark parts of crankles are here called Shallows. The small 

 ones have no openings ; but in some larger ones apertures have been 

 perceived, through which the opake part of the sun was discernible. 

 They are thought to be of the same nature as flats, and are perhaps 

 at the same depth below them as the flats are below the general 

 surface of the sun. 



7 . Dimples are small depressions, or indentures, and often contain 

 very small openings. They differ from crankles chiefly in size. 



8. Lastly, the low places of dimples are called Punctures. These 

 increase sometimes, and become openings, and at other times vanish 

 very rapidly. 



Having thus enumerated, according to his new nomenclature, the 



