on the Planet Venus. 
141 
2 d of April at 10* 15' in the evening , there are 20 days 11 hours 
and 15 minutest which, with a period of rotation of 23^ 21', di- 
vide into 21,005 revolutions , exact to the inconsiderable fraction 
°f 1 060’ 
April 3d, g h 40' p. m. with 160 and 370 magnifying powers, 
I found Venus again irregular in single parts of the arch ter- 
minating the illumination. That is, according to fig. 13, (Tab. 
XIV.) it sunk in somewhat, but very little, at a, and between 
a and b it protruded out a very little. Both horns, however, 
were pointed, and no spot could be seen. 
At 6 h 48', the boundary of light went in a little at d also, 
according to fig. 14. 
At f 25', I found both horns alike pointed, and no striking 
difference whatever, as the evening before. No spot. 
At 8* io', the same. No perceptible difference in the horns. 
At cp 50', I found the southern horn visibly, though not much, 
rounded as yesterday. Mr. Tjschbein saw it so likewise : but 
Venus was already too low, and undulated in the vapours, so 
that we could not reckon on this observation with confidence ; 
yet it agreed with the former. 
April 4, at 5 h 50' p. m. with a magnifying power of 160 
Venus appeared extraordinarily plain and fine, but without 
spots. The light lost itself in a dim grey at the boundary of 
illumination, which appeared somewhat uneven, as it did yes- 
terday about the same time, but both horns looked equally 
sharp. 
Without thinking of it in the l^ast, I saw, with a power of 
288, that the southern horn was somewhat slenderer than the day. 
before yesterday ; and this was confirmed with a power of 370, 
