24 The Saturnian System. (January, 
** August 2,1788, 21h.58m. 20-feet reflector; power 300. 
—Admitting the equatorial diameter of Saturn to lie in the 
direction of the ring, the planet is evidently flattened at the 
poles. I have often before, and again this evening, sup- 
posed the shape of Saturn not to be spheroidical (like that 
of Mars and Jupiter), but much flattened at the poles, and 
also a very little flattened at the equator; but this wants 
more exact observations.” 
The results observed in 1805 have been often quoted by 
myself and others. It appears, therefore, desirable to 
proceed to the results obtained in 1806 :— 
** April 16, 1806.—I examined the figure of the body of 
Saturn with the 7 and tro-feet telescopes, but they acted 
very indifferently ; and, were I to judge by present appear- 
ances, I should suppose the planet to have undergone a con- 
siderable change. Should this be the case, it will then be 
necessary to trace out the cause of such alterations.” 
‘‘April 1g. s10-feet; power 300.—The polar regions are 
much flattened. The figure of the planet differs a little 
from what it appeared last year. ‘This may be owing to the 
increased opening of the ring, which in four places obstructs 
now the view of the curvature in a higher latitude than it 
did last year. The equatorial regions, on the contrary, are 
more exposed to view than they have been for some time 
ASE. 
Then follow several observations indicating a close 
resemblance in 1806 to the figure which the planet had 
presented in 1805, when the flattening was first recognised. 
At length we have :— 
“‘May g. Power 527.—The air being very clear, I see 
the figure of Saturn nearly the same as last year; the flat- 
tening at the poles appears at present somewhat less; the 
equatorial and other regions are still the same.” 
These observations, combined with those made in 1805, 
and with subsequent observations by Schroter, Kitchener, 
Sir John Herschel, Coolidge, the Bonds, Airy, and others, 
seem to leave little doubt as to the occasional apparent ex- 
pansion of the planet in its temperate zones, and also as to 
other changes of figure sometimes limited to one hemisphere 
of the planet’s globe. 
I find it difficult to understand how these observations, 
made, be it observed, by experienced astronomers, can be 
explained as due to illusion. They accord perfectly well 
with the theory which I have advocated in the present essay 
and elsewhere. I would not indeed suggest that owing to 
any processes of expansion or contraction changes take 
