130 Mr. Schroeter's new Observations 
from these two careful observations alone we may conclude , very 
probably, the rotation to be nearly 23 hours 20 minutes ; which 
agrees extremely well with the approximate period of 23 hours 
21 minutes, which I have deduced from observations of two 
years, in my circumstantial memoir already quoted. 
Feb. 28, from io b 50' to n h 30', a. m. With powers 95, 160, 
and 209 of the 7-feet Schr. I found no spot, and both horns 
perfectly alike ; the light decreasing toward the boundary of 
illumination extremely plain, and the terminating arch of both 
horns, but particularly of the southern, rather unequal and 
knotty. 
At 3* io' to 26', with 160, 209, 370, and 632, a fine image ; 
the decreasing light seemed at the boundary of illumination to 
mix itself with the colour of the heavens, becoming equally 
faint. Both horns alike oval. 
At 4* 36', the same. 
tf 4', no difference. 
6', still the same. 
7', the southern horn began to acquire a pointed 
shape. 
9', it appeared already pointed ; the northern blunt 
as before. 
11', the southern exhibited the same appearance as 
both evenings before ; and I likewise perceived something 
darker making an impression into it. 
17', Venus behind clouds. 
if, through light clouds her southern horn was per- 
ceived to be pointed in comparison with the northern. 
37', the same in some clear intervals. The northern 
horn appeared always blunt. 
