the Nature of the Sun. 
285 
Ridges disperse very soon. 
Dec. 28, 1799. The appearance of the ridges I saw yester- 
day is much changed : they are less luminous and extensive than 
they were. The range is much broken ; and they appear more 
in detached irregular elevations. 
Dec. 29, 1799. The ridges are so much reduced to the resem- 
blance of the rest of the sun, that had I not known where to look 
for them, I should hardly have been able to trace any vestige 
of them. 
Feb. 9, 1800. The ridges which followed some openings 
Feb. 7, exist no longer. 
Different Causes of Ridges hinted at. 
Jan. 4, 1801. A crowd of ridges and nodules surround, and 
are interspersed among, a cluster of openings. A ridge which 
crosses one of the openings like a bar or bridge, is sharp on the 
following side, but shews thickness on the preceding. It seems 
probable, that the openings permit a transparent elastic fluid to 
come out, which disturbs the luminous matter on the top, so as 
to occasion ridges and nodules. There are not less than 17 
openings in the cluster. 
Jan. 6 , 1801. Following a set of openings lately come into 
the disk, are many luminous and broad, that is to say, high 
ridges, without any openings among them ; so that the cause 
which produces them acts probably below the shining matter. 
Their own levity also may occasion them to go into the higher 
regions. 
Jan. 30, 1801. Near the following margin is an extended 
plane, full of bright ridges and nodules, with a great number of 
