284 Dr. Heiischel’s Observations to investigate 
direction parallel, or nearly parallel, to the margin; and 'have 
the appearance of elevations. 
Jan. 29, 1801. Two sets of openings, near the north-follow- 
ing limb, have wide-spreading ridges about them : four other 
sets, being farther advanced into the disk, do not shew any. This 
denotes them to be thin elevations, which can only be seen near 
the circumference, by a side view. 
Feb. 8, 1801. Many ridges and nodules are now to be seen 
about the large opening, which yesterday had none. I suppose 
they are become visible by its advancement towards the margin, 
to which it draws near. 
Length of a Ridge. 
Dec. 27, 1 799. I measured one of the longest ridges in view. 
It extended over an angular space of 2', 45", 9, which is nearly 
75000 miles. 
Ridges generally accompany Openings. 
Feb. 5, 1801. Three sets of openings near the preceding 
limb, and two near the following one, are surrounded by lumi- 
nous ridges. 
Ridges are also often in Places where there are no Openings. 
Dec. 22, 1799. On the following side of the sun are luminous 
ridges ; but not within 50 or 60 degrees of an opening. 
Jan. 4, 1801. Towards the north, near the limb, is a collection 
of ridges without openings. 
Feb. 5. Two of the sets of openings of yesterday are gone; 
but have left extensive ridges behind. 
