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 opênings. 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
