on the Planet Venus. 143 
io* 5'. In this situation of Venus near the horizon, I tried 
again, by screwing the small speculum, and moving the image 
in the field, whether I could give her a false form, similar to 
that of the roundness of the southern horn on the 2d and 3d 
of April ; but both horns were, and remained, pointed. Con- 
sequently the observations of the 2d and 3d April were no 
deception, and they agree extremely well with the period of 
rotation, being the 5th and 6th new repeated proofs of it. 
April 7$, 6 h 30'. With power 160, both horns were equally 
pointed : no spot, nor any sensible inequality, except the dim 
faintness of the boundary of light, 
6 h 55', with 288, the same. 
7* 15', the same. 
7* 55', still the same. 
From the 7th to 12th of April cloudy weather. 
April 12 th, 6 h 30 ' p. m. With the same magnifying power 
both horns equally pointed. However, Venus was now become too 
narrow a crescent for a rounded shape of either horn to be expected . 
8* 20', the same, without perceptible inequality. 
A series of changeable bad weather. 
But on the 22 d of April in the evening, the hour not being 
marked in the journal, the southern horn appeared to be illu- 
minated only half as broad as the northern. 
April 23d, 5* 45', till after 6 h p. m. With 160 and 288, Venus 
was distinct, and her southern horn again much smaller than the 
northern, according to Jig. 1 6. 
But at io h there appeared no longer any striking difference. 
However Venus was already got too low, and I would never 
advise a careful observer to choose such a time for investiga- 
tions of this kind, 
