on the Planet Venus . 
135 
occasioned by a very fine glimmering pointed line of light , that 
ran on from the horn not far into the dark side, as at a, fig. 8. and 
was visible with all magnifying powers. I saw this line of light 
equally , whether I observed zvith the whole aperture, or covered 
a considerable part of it. 
It would be singular indeed, and most discouraging for all 
such observations, if so many appearances, agreeing together, 
and viewed with every precaution, should be merely deception, 
particularly as they usually and principally occurred only at 
the southern horn, without any reason that could be assigned 
if it be thought a fallacy. But if there be no deception, it 
follows incontrovertibly, that the surface of the southern hemi- 
sphere of Venus, like that of the moon, has the most and 
greatest inequalities. 
March 12th, 6 h if to 30' p. m. no kind of difference in the 
horns, no spot, or any other unusual appearance, could be 
seen with a power of 209. 
At 8 h , the same. 
But on the 13 th of March, from ii h to n h 20' a. m. I per- 
ceived, with the same magnifying power, a very evident and 
remarkable difference. The northern horn appeared pointed, but 
the southern was rounded, with a very small knot close upon it to 
the south, as at a, fig. 9. Thus I saw it with 160 and 288 mag- 
nifying powers ; and I even distinguished it with 95, though 
this was too small a power for so minute an object. On the 
northern horn I found nothing similar, notwithstanding I 
compared them repeatedly. Business called me away; and 
the atmosphere soon afterwards became cloudy, and continued 
so all day. 
This very remarkable observation is indeed not precisely the 
