Dr. Herschei/s Observations 
27b 
corners rounded off deeply, but not so much as to bring it to 
a spheroid. I see it in perfection. 
The four satellites that were last night on the preceding, ■ 
are now on the following side, and are very bright. 
I took a measure of the position of the four points of the 
greatest curvature, and found it 91 0 29'. This gives their lati- 
tude 45 0 44/, 5. I believe this measure to be pretty accurate. I 
set first the fixed thread to one of the lines, by keeping the 
north-preceding and south-following two points in the thread ; 
then adjusted the other thread in the same manner to the 
south-preceding and north-following points. 
May 5, 1805. I directed my 20-feet telescope to Saturn, 
and, with a power of about 300, saw the planet perfectly well 
defined, the evening being remarkably clear. The shadow of 
the ring on the body is quite black. All the other phenomena 
are very distinct. 
The figure of the planet is certainly not spheroidical, like 
that of Mars and Jupiter. The curvature is less on the equator 
and on the poles than at the latitude of about 45 degrees. 
The equatorial diameter is however considerably greater than 
the polar. 
In order to have the testimony of all my instruments, on the 
subject of the structure of the planet Saturn, I had prepared 
the 40-feet reflector for observing it in the meridian. I used a 
magnifying power of 360, and saw its form exactly as I had 
seen it in the 10 and 20-feet instruments. The planet is flat- 
tened at the poles, but the spheroid that would arise from this 
flattening is modified by some other cause, which I suppose to 
be the attraction of the ring. It resembles a parallelogram, one 
side whereof is the equatorial, the other the polar diameter, 
