Figure , Climate, Atmosphere, and Ring of Saturn. 457 
without trouble, would be sufficient to show the configurations 
of the changeable belts. 
Those who compare these figures, and others I have occa- 
sionally given, in which the particular shape of the body of 
the planet was not intended to be represented, with the 
figure which is contained in my last Paper, of which the 
sole purpose was to express that figure, and wonder at 
the great difference, have probably not read the measures I 
have given of the equatorial and polar diameters of this planet ; 
and as it may be some satisfaction to compare the appearance 
of Saturn in 1789 with the critical examination of it in 1805, 
I have now drawn them from the two papers which treat of 
the subject; Fig. 1, Plate XXI. represents the spheroidical 
form of the planet as observed in 1789, at which time the 
singularity of the shape since discovered was unknown ; and 
Fig. 2 represents the same as it appeared the 5th of May, 
1805. The equatorial and polar diameters that were esta- 
blished in 1789 are strictly preserved in both figures, and the 
last differs from the first only in having the flattening at the 
poles a little more extended on both sides towards the equa- 
torial parts. It is in consequence of the increase of the 
length of this flattening, or from some other cause, that a 
somewhat greater curvature in the latitudes of 40 or 45 
degrees north and south has taken place ; and as these dif- 
ferences are very minute, it will not appear extraordinary 
that they should have been overlooked in 1789, when my 
attention was intirely taken up with an examination of the 
two principal diameters of the planet. 
The use of various magnifying powers in observing minute 
objects is not generally understood. A low power, such as 
3N 2 
