PLANET SATURN. 393 



we find the gibbosity of the planet in the given situation, 

 and ascertain that the defalcation of light could not then 

 amount to the one-hundredth part of a second of a de- 

 gree, and that consequently no error could arise from 

 that cause. 



I have divided the folio viring observations into two 

 heads, one relating entirely to the figure of the body of 

 Saturn, the other concerning the physical condition or 

 climate and atmosphere of the planet. 



Ohser-oations of the Figure of Saturn. 



In the collectipn of my observations on the planet Sa- Observation* 

 turn, I have met with one made eighteen years ago, which J^^e pfan^t '^^ ° 

 is perfectly applicable to the present subject, and is as Suspicion in 

 follows; 1788 that Sa- 



August 2, 1788, 21^ 58'. 20-feet yeflector, power spheroidal. 

 300. Admitting the equatorial diameter of Saturn to He 

 in the direction of the ring, the planet is evidently flat- 

 tened at the poles. I have often before, and again this 

 evening, supposed the shape of Saturn not to be sphe- 

 roidical, (like that of Mars and Jupiter,) but much flat- 

 tened at the poles, and also a very little flattened at the 

 equator, but this wants more exact observations. 



April 16, 1806. I examined the figure of the body of observation* 

 Saturn with the 7 and 10-feet telescopes, but they acted shewing the 

 very indifferently, and, Avere I to judge by present ap- apparentfigure 

 T 1. 11 .11.°,, of Saturn and 



pearances, 1 should suppose the planet to have undergone ^ht variations 



a considerable change ; should this be the case, it will it is subject to. 

 then be necessary to trace out the cause of such 

 alterations. 



April 19. lO.feet, power 300. The polar regions 

 are much flattened. The figure of the planet differs &, 

 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 io view than they have 

 been for some time past. 



May 2. 10-feet, power 375. The polar regions are 

 much flatter than the equatorial; th<j latter being more 

 disengaged from the ring appear rather more curved than 



4ast 



