the Nature of the Sun. 289 
at Slough, He saw the same phenomena ; and judged of their 
being a link in the chain of appearances, as I did. 
We drew a small sketch of the place of the phenomena, 
merely to serve us to communicate our observations to each 
other.* 
i h 19'. A, is a small opening, without a shallow, which we 
had fixed upon, by way of enabling us to find again the minute 
objects which were to be examined. B, is the indentation, or 
dark place, of a corrugation I pointed out to Dr. Wilson. C, is 
a dark place of a corrugation he pointed out to me. 
i h 24'. We both found the dark part of the corrugation 
B gone ; and C had either changed its place or was vanished. 
ih 34'. C, was certainly gone. 
Dr. Wilson pointed out another round pore, which we had 
not perceived before, at some distance; also a largish indenta- 
tion near the opening, which guided our research. Shortly after, 
we found the indentation gone; and the pore was further 
removed from the opening. 
of indentations. 
The dark Places of Corrugations are Indentations. 
Dec. 27, 1799. That the low places of the corrugations are 
not much depressed, is evident from their visibility pretty near 
the margin of the sun. 
Jan. 27, 1800. The corrugations in many places are so 
coarse, that their indentations resemble small shallows. The 
MDCCCI. 
See Plate XIX. Fig. i8. 
Pp 
